The effect of 17α-methyltestosterone a 17β-estradiol on sex of livebearer fish Poecilia reticulata and P. wingei was studied. Solution of 2.5 mg testosterone was added in the aquarium the first and fifteenth day after delivery of new fry. Estrogen was administered in food to gravid females (400 mg per 1 kg food). Sex of all individuals was determined in one, two and three months. Administration of neither testosterone nor estrogen caused sex reversal; in the second case reproduction of almost all females was stopped.

Rhynchosciara americana é estudada desde a década de 50 quando foi evidenciada a amplificação gênica em regiões de seus cromossomos politênicos. Os fenômenos de amplificação e a formação destes cromossomos gigantes se dão por meio da ocorrência de endociclos, regulados pela oscilação na atividade do complexo ciclinaE/CDK2. Nas glândulas salivares de nosso modelo, durante o desenvolvimento, há ocorrência de cromossomos politênicos. Foi seqüenciada uma mensagem de uma quinase dependente de ciclina (CDK10) que não apresenta qualquer ligação com os endociclos, descrita na literatura. Este transcrito teve sua sequencia revelada por experimentos de 5\'RACE. A sequência genômica foi parcialmente determinada. O perfil de expressão deste gene foi determinado nos ovários, glândulas salivares e corpo gorduroso. A presença da proteína CDK10 foi determinada por experimentos de western blot em glândulas salivares. A localização celular foi determinada nos ovários. Resultados sugerem a existência de duas isoformas deste gene nos tecidos analisados. / Rhynchosciara americana is studied since the 50s decade when gene amplifications was discovered in some regions of its polytene chromosomes. The phenomena of amplification and the formation of these giant chromosomes happens through the endocycles, regulated by an activity oscillation of the complex CyclinE/CDK2. It is known that, in the salivary glands of our model, during it is development, there is the occurrence of these polytene chromosomes, formed since the beginning of the larval life. It was sequenced a message of CDK10, a cyclin depended kinase that shows no participation with the endocycles, as described at the literature. This transcript was fully sequenced by 5\'RACE experiments. Its genomic sequence was partially determined. The relative expression pattern was determined for ovaries, salivary glands and fat body. The CDK10 protein was observed by western blot experiments in the salivary glands. Its cellular location was determined at the ovaries. Results suggest the existence of two isoforms of the RaCDK10 gene at the tissues analyzed.

Objetivo: Investigar a presença de alterações (deleção e/ou duplicação) na região 22q11 em indivíduos até 02 anos de idade com fissura de palato, com o intuito de realizar diagnóstico precoce da síndrome da deleção 22q11 (SD22q11). Local: Laboratório de Genética e Citogenética Humana, HRAC/USP, Bauru-SP. Casuística e metodologia: Foram selecionados 55 indivíduos, de ambos os sexos, com idade até 2 anos e com fissura de palato, cadastrados e em tratamento no Hospital de Reabilitação de Anomalias Craniofaciais/USP. Todos os indivíduos foram analisados utilizando citogenética convencional por bandamento G e pela técnica de MLPA. Resultados e discussão: Foram analisados 55 indivíduos, dos quais 46 apresentaram fissura de palato isolada, 6 apresentaram fissura de palato e cardiopatia, 1 fissura de palato e atraso no desenvolvimento neuropsicomotor, 1 caso apresentou fissura de palato submucosa e 1 caso com fissura de palato submucosa e atraso no desenvolvimento neuropsicomotor. Não foram observadas anomalias cromossômicas numéricas ou estruturais por meio da análise citogenética. Embora não tenhamos encontrado nenhuma alteração, a análise citogenética inicial foi importante para detectar possíveis alterações em outras regiões cromossômicas que pudessem resultar em um fenótipo semelhante ao da SD22q11. Também não foram detectadas deleção ou duplicação na região 22q11 pela técnica de MLPA, a qual se mostrou um método rápido, sensível, eficaz e com um custo relativamente baixo em comparação a outras técnicas, para a investigação de alterações na região 22q11. Nossos resultados, associados aos da literatura, demonstram que a prevalência da deleção 22q11 nos casos de fissura de palato isolada é muito baixa. Mesmo sendo considerada como sugestiva da SD22q11, não detectamos nenhuma alteração na região 22q11 nos 6 indivíduos com cardiopatia. Somente foi possível identificar atraso no desenvolvimento em 2 indivíduos, ambos com dois anos de idade. Isso demonstra a dificuldade de realizar diagnóstico em idade precoce. Conclusão: O teste de rotina para investigação da deleção/duplicação da região 22q11 não se justifica em crianças com idade até dois anos que apresentam fissura de palato como principal achado clínico. Esses indivíduos devem ter um acompanhamento clínico criterioso, porque um comprometimento comportamental ou mental, bem como as características dismórficas da SD22q11 podem evoluir com o tempo. Devido ao tamanho relativamente pequeno desse estudo, e os dados inconsistentes da literatura atual, mais estudos são necessários para estabelecer critérios para indicação da rotina de investigação de deleção/duplicação 22q11 em indivíduos com anomalias palatinas. / Purpose: To investigate alterations (deletions/duplications) in the 22q11 region in individuals with cleft palate aged 0-2 years, in order to perform early diagnosis of 22q11 deletion syndrome (SD22q11). Local: Genetics and Human Cytogenetics Laboratory, HRAC/USP, Bauru-SP. Methods: We selected 55 individuals with cleft palate, both genders, registered and in treatment at Hospital de Reabilitação de Anomalias Craniofaciais/USP. All individuals were investigated by cytogenetics and MLPA techniques. Results and Discussion: 46 out of 55 individuals, presented isolated cleft palate, 6 cleft palate and heart malformations, 1 cleft palate and developmental delay, 1 submucous cleft, and 1 submucous cleft and developmental delay. G karyotype did not show any chromosomal abnormalities. Although we did not detect any alterations, the initial cytogenetics analysis was important to exclude alteration in other chromosomal region that could result in a similar phenotype. Deletion or duplication in 22q11 region by MLPA was not detected, which shown to be a rapid, sensitive, and low cost method in comparison with other methods to investigate 22q11 region. Results, associated with the literature, have shown that the prevalence of the 22q11 alteration is very low in cleft palate. The presence of heart malformation is suggestive of 22q11DS. Besides, there were no alterations in 22q11 region in 6 patients with cleft palate and heart malformations. We were able to identify developmental delay in only 2 individual, both aged 2 years which demonstrates the difficulty of making early diagnosis. Conclusion: There is no justification for routine screening for 22q11 region deletion/duplication in children aged 0-2 years with cleft palate as main feature. These individuals should be carefully followed because behavioral or mentalimpairments as well as dysmorphic features characteristic of 22q11DS may evolve with time.

Este trabalho é uma contribuição para um maior conhecimento da fauna através do inventário de Squamata e do estudo cromossômico de algumas espécies do continente e ilhas do Município de Cananéia, litoral sul do Estado de São Paulo. Ilhas estudadas: Ilha do Bom Abrigo, Ilha de Cananéia e Ilha do Cardoso. A amostragem de fauna de Squamata foi efetuada através de um gradiente altitudinal do nível do mar até cerca de 300 m, durante 30 meses, outubro de 2003 a abril de 2006. Foram utilizados os seguintes métodos de amostragem: procura limitada por tempo, coleta em estrada, coleta de terceiros, armadilhas de interceptação e queda. No continente e nas ilhas foram coletadas 25 espécies de serpentes, sete espécies de lagartos e uma espécie de anfisbena. Pesquisas em coleções herpetológicas e em trabalhos científicos acrescentaram oito espécies de serpentes e uma espécie de lagarto. O Município de Cananéia portanto tem como inventário geral a listagem de 33 espécies de serpentes, oito espécies de lagartos e uma espécie de anfisbena. Listas de espécies são apresentadas para cada ilha: Ilha do Bom Abrigo com duas espécies de serpentes e uma espécie de lagarto; Ilha de Cananéia, com 20 espécies de serpentes, três de lagartos e uma de anfisbena; Ilha do Cardoso, com 22 espécies de serpentes, seis de lagartos e uma de anfisbena. No Município de Cananéia, em todas as áreas estudadas, as serpentes Liophis miliaris e Bothrops jararacussu e o lagarto Enyalius iheringii apresentaram um maior número de indivíduos coletados. Nas coletas da Ilha de Cananéia as espécies de serpentes mais comuns foram Liophis miliaris e Sibynomorphus neuwiedi e a espécie de lagarto Hemidactylus mabouia. As espécies mais comuns na Ilha do Cardoso foram as serpentes Bothrops jararacussu e Spilotes pullatus e o lagarto Enyalius iheringii. Nenhuma das curvas de rarefação feitas para os métodos de amostragem atingiram a assíntota. Os estudos cromossômicos, em coloração convencional, foram feitos em cinco espécies de lagartos e uma espécie de anfisbena. Os cariótipos das espécies Colobodactylus taunayi e Diploglossus fasciatus foram descritos pela primeira vez. Os cariótipos descritos para espécies em populações de ilhas não apresentaram diferenças no número e na morfologia dos cromossomos em relação às espécies de populações do continente. / This study is a contribution to the knowledge of the fauna inventory and of the chromosomes of snake, lizard, and amphisbaenian species of continental and insular areas of Cananéia, the southern littoral of the state of São Paulo. Three islands were studied: Bom Abrigo, Cananéia, and Cardoso. Sampling of Squamata fauna was carried out for altitudes from sea level up to about 300 meters from October 2003 to April 2006. Sampling methods used: time limited search, road samplings, population donations, and pit falls. Both on the continent and the islands, 25 snake, 7 lizard, and one amphisbaenian species were collected. Herpetological collections and the scientific literature were surveyed and contributed with eight more snake and one lizard species. Both continental Cananéia and the islands had a general inventory of 33 snake, 8 lizard and one amphisbaenian species. A general species list was drawn up as well as one for each of the three islands studied: Bom Abrigo with two snake and one lizard species; Cananéia Island with 20 snake, three lizard and one amphisbaenian species and Cardoso with 22 snake , 6 lizard and one amphisbaenian species. In the studied areas, the most common snake species were Liophis miliaris and Bothrops jararacussu and the most common lizard species was Enyalius iheringii. On the island of Cananéia, Liophis miliaris and Sybinomorphus neuwiedi were the most sampled snake species and Hemidactylus mabouia, the most sampled lizard species. Bothrops jararacussu and Spilotes pullatus and the lizard Enyalius iheringii were the most commonly collected on Cardoso Island. The rarefaction curves for the methods used for our samples did not reach an asymptote. Chromosomal studies on five lizard species and one amphisbaenian species were carried out. Conventional staining was used in the cytological preparations. The karyotypes for the species Colobodactylus taunayi and Diploglossus fasciatus were described for the first time. There are no differences in the karyotype descriptions in the number and morphology of the chromosomes for the continental and island populations studied.

Lam, Yuk Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 142-157). / Abstracts in English and Chinese. / ABSTRACT --- p.i / 摘要 --- p.iv / ACKNOWLEDGEMENTS --- p.vi / CONTRIBUTORS --- p.viii / PUBLICATIONS --- p.ix / LIST OF TABLES --- p.x / LIST OF FIGURES --- p.xi / LIST OF ABBREVIATIONS --- p.xiii / TABLE OF CONTENTS --- p.xiv / Chapter SECTION I: --- BACKGROUND --- p.1 / Chapter CHAPTER 1: --- PRENATAL DIAGNOSIS OF FETAL ANEUPLOIDIES --- p.2 / Chapter 1.1 --- The need for prenatal screening and diagnosis --- p.2 / Chapter 1.2 --- Patau Syndrome (Trisomy 13) --- p.2 / Chapter 1.3 --- Current methods for fetal aneuploidy detection --- p.4 / Chapter 1.3.1 --- Routine prenatal screening tests --- p.4 / Chapter 1.3.2 --- Definitive prenatal diagnosis by invasive procedures --- p.7 / Chapter 1.4 --- New approach for noninvasive prenatal diagnosis --- p.11 / Chapter 1.4.1 --- Circulating fetal cells --- p.11 / Chapter 1.4.2 --- Cell-free fetal nucleic acids in maternal circulation --- p.12 / Chapter 1.4.3 --- Diagnostic applications of cell-free fetal nucleic acids in maternal plasma --- p.12 / Chapter CHAPTER 2: --- DEVELOPMENT OF FETAL EPIGENETIC MARKERS IN MATERNAL PLASMA --- p.17 / Chapter 2.1 --- Limitations of fetal DNA markers --- p.17 / Chapter 2.2 --- DNA methylation is an actively-researched area under the field of epigenetics --- p.18 / Chapter 2.3 --- Genome-scale DNA methylation analysis brings new insight into epigenetics --- p.20 / Chapter 2.4 --- The first demonstration of using an epigenetic method for detecting maternally-inherited fetal DNA in maternal plasma --- p.22 / Chapter 2.5 --- The first universal marker for fetal DNA in maternal plasma --- p.24 / Chapter 2.6 --- Discovery of more fetal epigenetic markers --- p.25 / Chapter 2.6.1 --- Methylated fetal epigenetic markers are more desirable --- p.25 / Chapter 2.6.2 --- Discovery of hypermethylated fetal epigenetic markers by studying tumor suppressor genes --- p.26 / Chapter 2.6.3 --- Discovery of hypermethylated fetal epigenetic markers on chromosome 21 --- p.28 / Chapter 2.7 --- Noninvasive detection of fetal aneuploidies using fetal epigenetic markers --- p.29 / Chapter 2.7.1 --- Noninvasive detection of fetal trisomy 18 by the epigenetic allelic ratio (EAR) approach --- p.29 / Chapter 2.7.2 --- Noninvasive detection of fetal trisomy 21 by the epigenetic-genetic (EGG) approach --- p.30 / Chapter 2.8 --- Aim of thesis --- p.32 / Chapter SECTION II: --- MATERIALS AND METHODS --- p.34 / Chapter CHAPTER 3: --- METHODS FOR QUANTITATIVE ANALYSIS OF DNA METHYLATION --- p.35 / Chapter 3.1 --- Subject recruitment and sample collection --- p.35 / Chapter 3.2 --- Sample processing --- p.38 / Chapter 3.3 --- DNA extraction --- p.38 / Chapter 3.3.1 --- Placental tissues --- p.38 / Chapter 3.3.2 --- Maternal blood cells --- p.39 / Chapter 3.3.3 --- Maternal plasma --- p.40 / Chapter 3.4 --- Methylated DNA immunoprecipitation and tiling array analysis (MeDIP-chip) --- p.41 / Chapter 3.4.1 --- Principles --- p.41 / Chapter 3.4.2 --- DNA sample and array processing --- p.43 / Chapter 3.4.2.1 --- DNA preparation and target hybridization --- p.43 / Chapter 3.4.2.2 --- Data analysis --- p.44 / Chapter 3.5 --- DNA methylation analysis on randomly-chosen regions on chromosome / Chapter 3.6 --- Bisulfite conversion --- p.46 / Chapter 3.6.1 --- Principles of bisulfite conversion --- p.46 / Chapter 3.6.2 --- Procedures of bisulfite conversion --- p.46 / Chapter 3.7 --- Quantitative analysis of DNA methylation --- p.47 / Chapter 3.7.1 --- Bisulfite PCR and genomic sequencing --- p.47 / Chapter 3.7.1.1 --- Primer design for bisulfite polymerase chain reaction (PCR) --- p.47 / Chapter 3.7.1.2 --- Bisulfite PCR --- p.49 / Chapter 3.7.1.3 --- Cloning --- p.50 / Chapter 3.7.1.4 --- Bisulfite genomic sequencing --- p.52 / Chapter 3.7.1.5 --- Data acquisition and interpretation --- p.53 / Chapter 3.7.2 --- EpiTYPER，a mass-spectrometry-based method --- p.54 / Chapter 3.7.2.1 --- Principles of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) --- p.54 / Chapter 3.7.2.2 --- Primer design of the EpiTYPER assay --- p.55 / Chapter 3.7.2.3 --- The EpiTYPER assay and its principle --- p.56 / Chapter 3.8 --- Methylation-sensitive restriction enzyme (MSRE)-mediated real-time quantitative PCR (qPCR) --- p.61 / Chapter 3.9 --- Digital PCR --- p.66 / Chapter 3.9.1 --- Principles of digital PCR --- p.66 / Chapter 3.9.2 --- Poisson distribution --- p.68 / Chapter 3.10 --- Statistical analyses --- p.69 / Chapter SECTION III: --- SYSTEMATIC IDENTIFICATION OF A FETAL DNA METHYLATION MARKER ON CHROMOSOME 13 FOR DETECTION OF FETAL TRISOMY 13 --- p.70 / Chapter CHAPTER 4: --- SYSTEMATIC IDENTIFICATION OF POTENTIAL FETAL EPIGENETIC MARKERS BY MEDIP-CHIP ANALYSIS --- p.71 / Chapter 4.1 --- Systematic discovery of fetal epigenetic markers on chromosome 13 by MeDIP-chip analysis --- p.71 / Chapter 4.2 --- Experimental design --- p.73 / Chapter 4.3 --- Results --- p.76 / Chapter 4.3.1 --- Identification of differentially methylated DNA regions by MeDIP-chip or non-MeDIP-chip approaches followed by EpiTYPER analysis --- p.76 / Chapter 4.3.2 --- Confirmation of differential methylation patterns and exclusion of regions with high inter-individual variations by EpiTYPER analysis --- p.82 / Chapter 4.3.3 --- Confirmation of differential DNA methylation patterns with higher resolution by bisulfite sequencing --- p.85 / Chapter 4.4 --- Discussion --- p.95 / Chapter CHAPTER 5: --- THE APPLICATION OF FETAL EPIGENETIC MARKER ON CHROMSOME 13 FOR DETECTION OF FETAL TRISOMY 13 --- p.98 / Chapter 5.1 --- Identification of a fetal epigenetic marker on chromosome 13 for the detection of fetal trisomy 13 by the epigenetic-genetic (EGG) chromosome dosage approach --- p.98 / Chapter 5.2 --- Experimental design --- p.101 / Chapter 5.3 --- Results --- p.105 / Chapter 5.3.1 --- Optimization of the digestion protocol --- p.105 / Chapter 5.3.2 --- Detection of digestion-resistant EFNB2-3'UTR moleculesin maternal plasma --- p.109 / Chapter 5.3.3 --- Evaluation of the fetal specificity of digestion-resistant EFNB2´ؤ3 'UTR DNA molecules in maternal plasma --- p.111 / Chapter 5.3.4 --- Comparison of EFNB2-3'UTR methylation profiles between the euploid and trisomy 13 placental tissue samples --- p.115 / Chapter 5.3.5 --- Chromosome dosage analysis by the EGG analysis using placental tissue samples --- p.118 / Chapter 5.4 --- Discussion --- p.122 / Chapter SECTION IV: --- CONCLUDING REMARKS --- p.125 / Chapter CHAPTER 6: --- CONCLUSION AND FUTURE PERSPECTIVES --- p.126 / Chapter 6.1 --- Development of fetal epigenetic markers for noninvasive prenatal diagnosis --- p.126 / Chapter 6.2 --- Systematic identification of fetal epigenetic markers on chromosome13 --- p.127 / Chapter 6.3 --- Detection of fetal trisomy 13 by the epigenetic-genetic (EGG) relative chromosome dosage analysis --- p.129 / Chapter 6.4 --- Future perspectives --- p.132 / Appendix I --- p.134 / Appendix II --- p.136 / REFERENCES --- p.142

La maturation méiotique des vertébrés diffère de la mitose par plusieurs aspects. J'ai étudié deux de ces particularités. 1) En méiose I, les chromosomes homologues sont ségrégés, en mitose, les chromatides sœurs sont séparées. En mitose, un mécanisme de contrôle bloque la cellule en métaphase en inhibant l'APC/C tant que tous les chromosomes ne sont pas correctement alignés sur le fuseau. En méiose I, des résultats contradictoires existent selon les espèces quant à l'existence d'un mécanisme de contrôle de ce type. J'ai montré que l'activité séparase (activité indirectement régulée par l'APC/C) est requise pour effectuer la transition métaphase/anaphase en méiose I, suggérant qu'un mécanisme de contrôle de ce type est requis chez la souris, organisme proche de l'homme. 2) A l'issue de la maturation méiotique, l'ovocyte reste bloqué en métaphase de méiose II en attendant la fécondation, alors que la mitose s'achève toujours. Ce blocage est dû à l'activité CSF et requiert la voie Mos/.../MAPK. J'ai montré que DOC1R, un nouveau substrat des MAPK, contrôle l'organisation des microtubules au cours de l'arrêt CSF. Ces résultats font évoluer la vision de l'arrêt CSF qui était considéré comme une voie linéaire aboutissant à la stabilisation du MPF. L'arrêt CSF est une voie non linéaire contrôlant aussi la morphologie de l'ovocyte.

<p>Sex chromosomes are useful for the study of how factors such as mutation, selection, recombination and effective population size affect diversity and divergence.</p><p>A comparison of gametologous introns in seven different bird species revealed a complete lack of diversity on the female-specific W chromosome. In contrast, Z had at least one segregating site in all examined species. This can be explained by the lower mutation rate and lower effective population size of W but also suggests that selection affects diversity levels on the non-recombining W chromosome.</p><p>In a diverse set of chicken breeds, the Z chromosome showed reduced diversity compared to autosomes and significant heterogeneity in levels of variation. High variance in male reproductive success, leading to a reduced Z chromosome effective population size, can partly explain this observation. In addition, we suggest that selective sweeps frequently act on the Z chromosome and are responsible for a significant part of the observed Z reduction. </p><p>Differences in the mutation rate of Z and W chromosome sequences indicate that the time spent in male germ line is important for the mutation rate, but does not exclude a specifically reduced mutation rate on the Z chromosome. Estimates of mutation rate in autosomal, Z- and W-linked chicken and turkey sequences indicate a slight reduction in the rate on Z. However, due to rate heterogeneity among introns this reduction is not significant and we cannot exclude male biased mutation as the single cause of rate variation between the chromosomal classes.</p><p>Analysis of indel mutation rates in avian and mammalian gametologous introns show frequent occurrence of indels on both W and Y, excluding meiotic recombination as the only source of this type of mutation. The different indel rate patterns in birds (Z>W) and mammals (X=Y) suggest that indels are caused by both replication and recombination.</p>

<p>Chicken and Japanese quail are commonly used models in developmental and sex specific neuroendocrine research. There is relatively little known about the mechanisms behind their sex specific brain development, especially regarding the impact of the sex chromosomes (male: ZZ, female ZW) in relation to gonadal hormones. This thesis explores several aspects of these processes. Gene expression analysis with cDNA and Affymetrix arrays on brain tissue from both pre-gonadal embryos and embryos with differentiated gonads indicate a strong sex chromosomal presence in sexual dimorphic somatic tissue development in both chicken and Japanese quail. This sex chromosome pattern seems to remain in adult brain tissue. The data demonstrates that chicken males exhibit a significant level of Z-gene dosage compared to females in both somatic and germ line derived embryonic tissues. Several avian sex determination gene candidates (MHM non-coding RNA, DMRT1, HINTW, and HINTZ) were analyzed by real-time PCR. DMRT1 is dosage compensated in male brain tissue, in contrast to its reported gene dosage in male gonads. Early embryonic ethinylestradiol (EE2) exposure did not affect male or female neural gene expression patterns during later development. A peptidomics analysis on quail embryonic day 12 (ed12) and ed17 diencephalon by LC-MS identified over 60 endogenous peptides and analyzed the expression patterns for 38 of them with regard to age, sex and early EE2 exposure. There was a general upregulation between ed12 and ed17, but no clear sex effects were detected. Multivariate analysis indicates that EE2 exposed individuals differ from control individuals in a gender independent manner, and that Gonadotropin-inhibiting hormone related peptide 2 (GnIH-RP2) is a candidate for EE2 induced peptidomic alterations in male embryonic brain.</p>

Chicken and Japanese quail are commonly used models in developmental and sex specific neuroendocrine research. There is relatively little known about the mechanisms behind their sex specific brain development, especially regarding the impact of the sex chromosomes (male: ZZ, female ZW) in relation to gonadal hormones. This thesis explores several aspects of these processes. Gene expression analysis with cDNA and Affymetrix arrays on brain tissue from both pre-gonadal embryos and embryos with differentiated gonads indicate a strong sex chromosomal presence in sexual dimorphic somatic tissue development in both chicken and Japanese quail. This sex chromosome pattern seems to remain in adult brain tissue. The data demonstrates that chicken males exhibit a significant level of Z-gene dosage compared to females in both somatic and germ line derived embryonic tissues. Several avian sex determination gene candidates (MHM non-coding RNA, DMRT1, HINTW, and HINTZ) were analyzed by real-time PCR. DMRT1 is dosage compensated in male brain tissue, in contrast to its reported gene dosage in male gonads. Early embryonic ethinylestradiol (EE2) exposure did not affect male or female neural gene expression patterns during later development. A peptidomics analysis on quail embryonic day 12 (ed12) and ed17 diencephalon by LC-MS identified over 60 endogenous peptides and analyzed the expression patterns for 38 of them with regard to age, sex and early EE2 exposure. There was a general upregulation between ed12 and ed17, but no clear sex effects were detected. Multivariate analysis indicates that EE2 exposed individuals differ from control individuals in a gender independent manner, and that Gonadotropin-inhibiting hormone related peptide 2 (GnIH-RP2) is a candidate for EE2 induced peptidomic alterations in male embryonic brain.

Sex chromosomes are useful for the study of how factors such as mutation, selection, recombination and effective population size affect diversity and divergence. A comparison of gametologous introns in seven different bird species revealed a complete lack of diversity on the female-specific W chromosome. In contrast, Z had at least one segregating site in all examined species. This can be explained by the lower mutation rate and lower effective population size of W but also suggests that selection affects diversity levels on the non-recombining W chromosome. In a diverse set of chicken breeds, the Z chromosome showed reduced diversity compared to autosomes and significant heterogeneity in levels of variation. High variance in male reproductive success, leading to a reduced Z chromosome effective population size, can partly explain this observation. In addition, we suggest that selective sweeps frequently act on the Z chromosome and are responsible for a significant part of the observed Z reduction. Differences in the mutation rate of Z and W chromosome sequences indicate that the time spent in male germ line is important for the mutation rate, but does not exclude a specifically reduced mutation rate on the Z chromosome. Estimates of mutation rate in autosomal, Z- and W-linked chicken and turkey sequences indicate a slight reduction in the rate on Z. However, due to rate heterogeneity among introns this reduction is not significant and we cannot exclude male biased mutation as the single cause of rate variation between the chromosomal classes. Analysis of indel mutation rates in avian and mammalian gametologous introns show frequent occurrence of indels on both W and Y, excluding meiotic recombination as the only source of this type of mutation. The different indel rate patterns in birds (Z&gt;W) and mammals (X=Y) suggest that indels are caused by both replication and recombination.