Fertilization and cleavage of bovine embryos depend not only on maternal involvement, but also on the paternal contributions that involve more than just providing the haploid male genome. Therefore, the overall objective of this project was to determine the impact of morphologically abnormal spermatozoa on fertilization, subsequent embryonic development, and embryo quality at the cellular level. Four experiments used morphologically abnormal semen samples collected and cryopreserved from four Holstein bulls before (Pre) and after a scrotal insulation (PI) period of 48 h. Zygotes were cultured for 8 d when a developmental score was assigned to each embryo; subpopulations were subjected to either the TUNEL or caspase assays to determine apoptosis. In the final experiment pronuclear decondensation for presumptive zygotes was evaluated by differential interference contrast microscopy at 3 h time intervals from 6 to 18 h post in vitro insemination (hpi). Morphological evaluation of semen samples revealed a decrease (P < 0.01) in the percentages of normal spermatozoa in the PI samples in comparison with the Pre samples for Bulls I and Bull III (74 to 22.3% and 67.7 to 0.5 %, respectively) and the scrotal insulation effects persisted from the time of cleavage through blastocyst formation for Bulls I and III and corresponded with a similar decrease in blastocyst development for PI samples in experiment 1 regardless of which semen separation method was used. Likewise, the overall pronuclear decondensation rate for the PI zygotes of Bull I and III showed no increase over time and remained predominantly at PN1 stage (1.5 ± 0.17; 1.8 ± 0.22, respectively). In contrast, the development for Bull II and Bull IV were unaffected. The embryo quality assessment revealed that the caspase intensity increased significantly for both Bull I (217 ± 147) and Bull III (229 ± 98) for the PI embryo groups compared to those of Bull II (98 ± 115) and Bull IV (90 ± 111). In conclusion, the tested separation methods used seemed inadequate in their ability to provide potentially competent sperm for IVF. The decrease in embryonic development appears to be multifaceted and related to the changes in head shape morphology and we suggest the failure in normal pronuclear formation is associated with an absence of normal decondensation of the penetrating spermatozoon. The inability to consistently measure apoptosis in early stage embryos complicates the assessment of differences in embryo quality. These observations support the hypothesis of uncompensable seminal traits in IVF with abnormal spermatozoa and provide compelling evidence that the effect of morphologically abnormal spermatozoa occurred prior to cleavage, thus is manifested during the early stages of fertilization. / Ph. D.

<p> PEA3 is a member of the ets family of transcription factors. It is expressed throughout embryonic development and in mouse mammary adenocarcinomas induced by expression of the receptor tyrosine kinase Neu. Mice lacking PEA3 due to a targeted disruption of the gene, develop normally, however, male mice fail to mate for yet undetermined reasons. To further understand the role of PEA3 in mammary gland development and tumorigenesis, the effects of loss of function of PEA3 were examined in tumor formation and in mammary gland development. </p> <p> Analysis of tumor formation in PEA3 +I+ and PEA3 -/-animals failed to show a statistically significant difference in tumor onset. Loss of PEA3 did not affect the tumor morphology, nor did it inhibit metastasis of these tumors to the lung. These data indicate that PEA3 is not required for tumor formation or metastasis. </p> <p> PEA3 deficient animals displayed defects in branching morphogenesis in the mammary gland. Decreased ductal branching was observed in virgin and pregnant females. Mice with decreased levels of PEA3 expression also exhibited defects in branching morphogenesis, indicating a dosage effect. PEA3 is expressed in the myoepithelial cells during puberty and pregnancy. It is also express in the highly proliferative cap cell layer of the terminal end bud. In the embryonic mammary gland, PEA3 is expressed as early as 10.5 days in the mammary epithelium and continues late in embryogenesis. Expression in the male mammary gland is lost at approximately embryonic day 16. </p> / Thesis / Candidate in Philosophy

A dissertation submitted to the Faculty of Dentistry, University of the Witwatersrand, Johannesburg, in part- fulfilment of the requirements for the Degree of Master of Science in Dentistry 1982 / Rat embryos of the post-implantation stage are grown on a static culture medium, for the purpose of assessing growth and development over a 2 day period. The technique used is referred to as the petri-dish culture chamber method. This involves the culture of rat embryos on rat serum, in a controlled environment. Postimplantation embryos from the 6,5 to 8 day stage, and consisting simply of the 3 germ layers, showed a 60% survival rate in. vit/io after 2h hours and A8 hours respectively. After a full A8 hours in vitfio the embryos demonstrated well developed beating hearts, and a neural groove in the process of closing. The survival rate of embryos explanted at later stages was not as successful. The results compare favourably with the results of other workers, using the same method of culture. An advantage of the petri-dish culture chamber is that it allows for easy experimental access to the embryos at all times;a factor to be considered in any technique involving surgical intervention. Although more sophisticated methods have since superseded the static environment petri-dish technique, it is recommended here that this method should not be totally replaced by the more modern circulating culture medium technique. / IT2017

Tabelas de estágio embrionário podem ser utilizadas para detectar semelhanças e diferenças de caracteres entre grupos e como ferramenta para estudos baseados na fase embrionária. Neste estudo, ovos do lagarto Iguana iguana foram utilizados para a elaboração de uma tabela de estágios e para determinar o padrão de excreção durante o desenvolvimento. Iguana é um modelo conveniente por produzir numerosas desovas de ovos de tamanho grandes, propiciando um fácil manuseio e um bom número de réplicas. Após a oviposição, 18 estágios embrionários foram determinados durante os quais uréia foi o resíduo nitrogenado principal. Apesar do iguana ser o primeiro lagarto estudado, o padrão ureotélico é comum entre a maioria das espécies reptilianas estudadas até o momento. A casca pergaminácea permite que os ovos dobrem em massa devido à absorção de água, e o mecanismo pelo qual os embriões lidam com a diluição e osmolaridade resultante é um tema interessante para futuros trabalhos e comparações com espécies de cascas rígidas. Há evidência de desenvolvimento heterocrônico dos membros e o desenvolvimento de iguana é similar ao do lagarto Anolis sagrei, também do clado Iguania. Mais estudos de desenvolvimento de lagartos são necessários e a utilização de critérios morfológicos similares para facilitar a comparação de eventos embrionários. / A Table of embryonic stages can be used to detect similarities and differences in developmental features between groups and as a tool for studies based on embryonic phase. In this study, eggs of the lizard Iguana iguana were used to elaborate a staging table and to determine the nitrogen excretion pattern during the development. Iguana is a convenient model for having a large clutch of large eggs, allowing an easy handling and a good number of replicates. After oviposition embryonic stages were determined during which urea was the main nitrogen waste. Although iguana is the first lizard studied, the ureotelic pattern is common among the majority of reptilian species so far studied The pergaminaceous shell allows that the eggs double in mass due to water absorption, and the mechanism and how the egg deals with dilution and resultant osmolarity is an interesting issue for future works and comparisons with species of rigid eggshells. There is evidence of heterocronic development of the limbs and the development of iguana is similar to the lizard Anolis sagrei, also from the clade Iguania. Further studies on lizard evelopment are required and the use of similar morphological approach to facilitate comparisons of embryonic events

Os primeiros trabalhos em desenvolvimento embrionário de opiliões tiveram início no final do século XIX, enfocando principalmente espécies holárticas, e desde o final da década de 1970 o assunto não foi mais abordado. Visando retomar este tema com um componente comparativo, o presente estudo objetivou a descrição do desenvolvimento embrionário de quatro subfamílias de Gonyleptidae (Opiliones Laniatores), a saber: Caelopyginae (Ampheres leucopheus), Goniosomatinae (Goniosoma proximum e Goniosoma spelaeum), Mitobatinae (Longiperna zonata e Promitobates ornatus) e Progonyleptoidellinae (Iporangaia pustulosa). Dados adicionais obtidos para outras espécies foram incluídos com fins comparativos. O desenvolvimento dos embriões foi acompanhado através de fotografias digitais diárias de ovos em diversas desovas de cada espécie. Ovos de ambas as espécies de Goniosomatinae (que apresentam cuidado materno das desovas) são depositados com aproximadamente 1,5 1,6 mm, atingindo 2,1 mm em G. proximum e 2,3 mm in G. spelaeum próximos à eclosão, ao passo que em A. leucopheus e I. pustulosa (que apresentam cuidado paterno) apresentam 1,13 mm e 1,30 mm logo após a deposição, e 1,35 mm e 1,59 mm próximos à eclosão, respectivamente. Foram observadas e descritas diferenças entre as espécies estudadas pelo presente, tanto na coloração do vitelo e transparência do córion como em características morfológicas e na seqüência de eventos, em especial no padrão de pigmentação. A duração do período embrionário foi de 29-56 dias em A. leucopheus, 35-66 dias em I. pustulosa, 3148 dias em G. proximum, 2954 dias em G. spelaeum, 43-64 dias em L. zonata e 35-55 dias in P. ornatus. Dentre as espécies estudadas a duração relativa de cada fase variou bastante, com a clivagem correspondendo a 3-4% do período embrionário, a formação da banda germinativa a 9-14%, a metamerização do prossoma a 3-13%, a inversão do embrião a 21-38%, a organogênese larval a 22-42% e a fase larval no ovo a 7-28%. / The first studies concerning the embryonic development of harvestmen started in the late XIX century, mostly concerning holarctic species, and the last studies appeared during the late 1970s. Aiming at filling a gap of more than 30 years in the study of embryology of harvestmen, and adding a comparative component, this study focused on the embryonic development of species of four subfamilies of Gonyleptidae harvestmen (Laniatores), namely Caelopyginae (Ampheres leucopheus), Goniosomatinae (Goniosoma proximum and Goniosoma spelaeum), Mitobatinae (Longiperna zonata and Promitobates ornatus) and Progonyleptoidellinae (Iporangaia pustulosa). Additional data acquired for other species is also included for comparison purposes. The embryonic development was followed in the field, by taking daily photographs of different eggs from a number of egg batches during about two months. Eggs of both species of the subfamily Goniosomatinae (which present maternal care of batches) are laid with ca. 1.5 1.6 mm in diameter, reaching ca. 2.1 mm in G. proximum and 2.3 mm in G. spelaeum near hatching, whereas recently laid eggs of A. leucopheus and of I. pustulosa (which present paternal care) have approximately 1.13 mm and 1.30 mm in diameter, respectively, reaching diameters of about 1.35 mm and 1.59 mm, respectively, close to hatching. Differences concerning yolk coloration and eggshell transparency were observed and are described for the presently studied species, as well as differing morphological features and sequence of events, particularly in reference to the pigmentation pattern. The duration of the embryonic phase was 29-56 days in A. leucopheus, 35-66 days in I. pustulosa, 3148 days in G. proximum, 29-54 days in G. spelaeum, 43-64 days in L. zonata and 35-55 days in P. ornatus. Amongst the species studied herein relative durations are quite variable, with cleavage corresponding to 3-4% of the embryonic development, germ band formation to 9-14%, prosoma metamerization to 3-13%, the inversion of the embryo to 21-38%, larval organogenesis to 22-42% and the larval phase in the egg to 7-28%.

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2006. / Härtill 7 uppsatser.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2008. / Härtill 3 uppsatser.

Thesis (Ph. D.)--University of Virginia, 2008. / Title from title page. Includes bibliographical references. Also available online through Digital Dissertations.