BACKGROUND: Alcohol dependence is more common among men than among women. Potential explanations for this include the role of genes in sex chromosomes (X and Y). In the present study, we scanned the entire Y chromosome and its homologs on the X chromosome in men to identify male-specific risk genes for alcohol dependence. METHODS: Two thousand nine hundred and twenty-seven individuals in two independent cohorts were analyzed. The European-American male cohort (883 cases with alcohol dependence and 445 controls) served as the discovery cohort and the European-American female cohort (526 cases and 1073 controls) served as a contrast group. All individuals were genotyped on the Illumina Human 1M beadchip. Two thousand two hundred and twenty-four single nucleotide polymorphisms (SNPs) on the Y chromosome or in the homologs on the X chromosome were analyzed. The allele frequencies were compared between cases and controls within each cohort using logistic regression analysis. RESULTS: We found that, after experiment-wide correction, two SNPs on the X chromosome were associated significantly with alcohol dependence in European-American men (P=1.0×10 for rs5916144 and P=5.5×10 for rs5961794 at 3′ UTR of NLGN4X), but not in the women. A total of 26 SNPs at 3′UTR of or within NLGN4X were nominally associated with alcohol dependence in men (5.5×10≤P≤0.05), all of which were not statistically significant in women. CONCLUSION: We conclude that NLGN4X was a significant male-specific risk gene for alcohol dependence in European-Americans. NLGN4X might harbor a causal variant(s) for alcohol dependence. A defect of synaptogenesis in neuronal circuitry caused by NLGN4X mutations is believed to play a role in alcohol dependence.

Skeletal muscle satellite cells (myoblasts) are the primary stem cells of skeletal muscle which contribute to growth, maintenance, and repair of the muscles. Satellite cells are the first stem cells used for cellular cardiomyoplasty more than 20 years ago. The isolation, culture, labeling, and identification of satellite cells are described in detail here. The implantation and outcomes of cellular cardiomyoplasty using satellite cells have been summarized in the previous chapter (Chapter 1).

A comprehensive population study in the Middle East was conducted using different genetic markers in order to establish a wider genetic profile of the Middle Eastern populations. The main goal of this study was to analyze DNA from samples collected from different locations, and produce genetic motifs and patterns that could be used to identify and distinguish the target populations. This information will allow us to analyze the ancestry of these populations, their interactions through time and space, and the effects these interactions have on the populations' structure. We have collected around 1300 individual samples from different populations in the Middle East ranging from Oman in southern Arabia, to the West Bank and Gaza in Palestine. Our samples can be divided into two primary groups: 320 samples come from Oman; this region is important because of its geographical proximity to Yemen which is perceived as the historical area where the Arabs originated and 800 samples came from Palestine, a central region in the Middle East that connects Asia and Africa and was a passageway between the two continents through history. The samples collected from Oman have genealogy charts that were provided by the participants, while the samples from Gaza lack the genealogy charts. DNA was extracted from the samples, amplified using PCR technology, sequenced and genotyped using non-recombining genetic markers. Short Tandem Repeats(STR) were screened in the samples.A specific STR marker, DYS458, exhibited an alternative allele at repeat number 18 which was a 2 base pair shift identified as microvariant 18.2. The samples showed an unusually high frequency of microvariant 18.2.When microvariant 18.2 haplotype was combined with Modal Cohen Haplotype (MCH) motifs, we were able to infer some genetic characteristics about our samples. The Cohen Modal haplotype was used in combination with the results of the 18.2 DYS458 analyses to construct a snapshot of the Middle East, using NETWORK software to analyze the relationship within and between the samples from Oman, which is located in Southern Arabia, and the areas North of Arabia (Jordan, Syria, and Palestine), which is also known as the Levant.

The potential value of the Y chromosome for forensic applications has been recognized for some time with the current work dedicated to Short Tandem Repeat analysis and Single Nucleotide Polymorphism (SNP) discovery. This study examined the ability of two different SNP analysis methods to determine if they could be utilized in forensic applications and ultimately be developed into an established system for Y chromosome SNP analysis. This study examined two principle SNP analysis systems: single base extension and Pyrosequencing. Pyrosequencing was determined to be superior to single base extension, due to the wealth of information provided with sequencing and the flexibility of designing primers for analysis. Using Pyrosequencing, 50 Y chromosome loci were examined and the minimum loci required for maximum diversity for the development of a Y chromosome SNP analysis system were chosen. Thirteen loci were selected based on their ability to discriminate 60 different individuals from three different racial groups into 15 different haplogroups. The Y chromosome SNP analysis system developed utilized nested PCR for the amplification of all 13 loci. Then they were sequenced as groups, ranging from one to three loci, in a single reaction. The Y chromosome SNP analysis system developed here has the potential for forensic application since it has shown to be successful in the analysis of blood, buccal swabs, semen, and saliva, works with as little as 5 pg of starting DNA material, and will amplify only male DNA in the presence of male/female mixtures in which the female portion of the sample overwhelmed the male portion 30,000 to 1.

Aside from few model organisms, little is known about early embryonic development or sex determination in insects, in particular mosquitoes which are major vectors of worldwide disease. The goals of this work were to investigate a mosquito-specific transcription factor and its intronic miRNA cluster and characterize a novel Y chromosome gene in An. stephensi. The aims of these experiments were to expand on the knowledge of genes involved in embryonic development and sex determination with potential application in vector control strategies. In Ae. aegypti a mosquito-specific bZIP1 transcription factor was demonstrated to be conserved among divergent mosquito species. It was maternally and zygotically-expressed and knock-down of bZIP1 mRNA via siRNA microinjection in the embryo resulted in embryonic death. The expression profile of this gene was determined through the use of RT-PCR and qRT-PCR. Additionally, this gene contains a miRNA cluster that is also relatively conserved amongst members of the Culicidae family suggesting its evolutionary importance. The miRNAs are also maternally and zygotically expressed and are the most abundant embryonic miRNAs as determined by small RNA sequencing and Northern analysis. Promoter activity for bZIP1 was characterized and the promoter was used to direct maternal and zygotic transgene expression in An. stephensi. Y chromosome genes were successfully identified in An. stephensi from Illumina sequencing data. This work focused on a gene unique to the Y 1 (GUY1). It was shown that GUY1 was male specific and linked to the Y chromosome. RT-PCR and single embryo analysis suggested that GUY1 was expressed during the maternal to zygotic transition and was only expressed in male embryos. It was shown in multiple transient and transgenic assays that the ectopic expression of GUY1 can influence the sex of subjected individuals and skew sex distribution to a male bias. There is still much to be investigated before a GUY1-based transgenic line can be tested and implemented for use in vector population control. However, the work in this dissertation represents a major step towards novel mosquito control strategies based on the manipulation of Y chromosome genes. / Ph. D.

Unlike the autosomes, the Y chromosome in humans and other primates has few protein coding genes, with only a few dozen single-copy genes and several tandem duplicated gene families, called the "ampliconic" genes. The interaction of many biological and evolutionary factors is responsible for this structural heterogeneity among different parts of the genome. We sequenced and assayed the copy numbers of Y-linked, single-copy genes and ampliconic genes in a group of closely related macaque monkeys, then fit models of gene family evolution to this data along with whole genome data from human, chimpanzee, and rhesus macaque. Our results (i) recovered evidence for several novel examples of gene conversion in papionin monkeys, (ii) indicate that ampliconic gene families evolve faster than autosomal gene families and than single-copy genes on the Y chromosome, and that (iii) Y-linked singleton and autosomal gene families evolved faster in great apes than they do in other Old World higher Primates. These findings highlight the evolutionary eccentricity of duplicated genes on the Y chromosome and suggest an important role for natural selection and gene conversion in the evolution of Y-linked gene duplicates. / Thesis / Master of Science (MSc)

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Markers on the non-recombining region of chromosome Y is a useful tool for study of diversity between populations. SNPs are the most commom polymorphisms in human genome. Mutation rate of SNPs is very low and so they may be used as genetic markers in evolutionary and population studies. We have analyzed 205 unrelated men from 11 Sub-Saharan Fulani's subpopulations. Fulani are an ethnic group of people spread over many countries, mainly in West Africa. Our samples are from Tindangou area, Banfora area (Burkina Faso), Bongor area, Linia area (Chad), Diafarabé area (Mali), Tcheboua area (Cameroon), Banfora area, Diffa area, Zinder area, Ader area and Abalak area (Niger). Using kit Signet Y-SNP Identification Systems and Luminex instrument with LabMAP Luminex Technology we detected particular Y chromosome's SNPs. LabMAP Luminex Technology is universal array platform, which as a probe using fluorescent polystyrene microspheres. We have observed 12 different haplogroups. Haplogroup E, which is typical African haplogroups, is determined with derivated allele in polymorfism M96. We have detected haplogroup E in maximum of 89,3% in the Fulani's subpopulations. In 7,8% we have detected haplogroup R, which is characteristic of populations in the Euroasia. Gene pool of Fulani's population is influenced with a...