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1.
PLoS One ; 16(3): e0248233, 2021.
Article in English | MEDLINE | ID: mdl-33755696

ABSTRACT

Structural variations (SVs) represent a large fraction of all genetic diversity, but how this genetic diversity is translated into phenotypic and organismal diversity is unclear. Explosive diversification of dog coat color and patterns after domestication can provide a unique opportunity to explore this question; however, the major obstacle is to efficiently collect a sufficient number of individuals with known phenotypes and genotypes of hundreds of thousands of markers. Using customer-provided information about coat color and patterns of dogs tested on a commercial canine genotyping platform, we identified a genomic region on chromosome 38 that is strongly associated with a mottled coat pattern (roaning) by genome-wide association study. We identified a putative causal variant in this region, an 11-kb tandem duplication (11,131,835-11,143,237) characterized by sequence read coverage and discordant reads of whole-genome sequence data, microarray probe intensity data, and a duplication-specific PCR assay. The tandem duplication is in an intronic region of usherin gene (USH2A), which was perfectly associated with roaning but absent in non-roaned dogs. We detected strong selection signals in this region characterized by reduced nucleotide diversity (π), increased runs of homozygosity, and extended haplotype homozygosity in Wirehaired Pointing Griffons and Australian Cattle Dogs (typically roaned breeds), as well as elevated genetic difference (FST) between Wirehaired Pointing Griffon (roaned) and Labrador Retriever (non-roaned). Surprisingly, all Dalmatians (N = 262) carried the duplication embedded in identical or similar haplotypes with roaned dogs, indicating this region as a shared target of selection during the breed's formation. We propose that the Dalmatian's unique spots were a derived coat pattern by establishing a novel epistatic interaction between roaning "R-locus" on chromosome 38 and an uncharacterized modifier locus. These results highlight the utility of consumer-oriented genotype and phenotype data in the discovery of genomic regions contributing to phenotypic diversity in dogs.


Subject(s)
Animal Fur/metabolism , Dogs/genetics , Extracellular Matrix Proteins/genetics , Animals , Dogs/metabolism , Epistasis, Genetic , Gene Duplication , Genetic Loci , Hair Color , Introns , Phenotype
2.
Mamm Genome ; 30(5-6): 166-172, 2019 06.
Article in English | MEDLINE | ID: mdl-31115595

ABSTRACT

Inbreeding depression has been demonstrated to impact vital rates, productivity, and performance in human populations, wild and endangered species, and in recent years, the domestic species. In all cases, standardized, high-quality phenotype data on all individuals are invaluable for longitudinal analyses such as those required to evaluate vital rates of a study cohort. Further, many investigators agree upon the preference for and utility of genomic measures of inbreeding in lieu of pedigree-based estimates of inbreeding. We evaluated the association of measures of reproductive fitness in 93 Golden Retrievers enrolled in the Golden Retriever Lifetime Study with a genomic measurement of inbreeding, FROH. We demonstrate a statistically significant negative correlation between fecundity and FROH. This work sets the stage for larger scale analyses to investigate genomic regions associated with fecundity and other measures of fitness.


Subject(s)
Fertility/physiology , Inbreeding Depression , Animals , Dogs/genetics , Dogs/physiology , Female , Fertility/genetics , Genome/genetics , Genotype , Homozygote , Inbreeding Depression/genetics , Phenotype , Polymorphism, Single Nucleotide/genetics
3.
PLoS Genet ; 14(10): e1007648, 2018 10.
Article in English | MEDLINE | ID: mdl-30286082

ABSTRACT

Consumer genomics enables genetic discovery on an unprecedented scale by linking very large databases of personal genomic data with phenotype information voluntarily submitted via web-based surveys. These databases are having a transformative effect on human genomics research, yielding insights on increasingly complex traits, behaviors, and disease by including many thousands of individuals in genome-wide association studies (GWAS). The promise of consumer genomic data is not limited to human research, however. Genomic tools for dogs are readily available, with hundreds of causal Mendelian variants already characterized, because selection and breeding have led to dramatic phenotypic diversity underlain by a simple genetic structure. Here, we report the results of the first consumer genomics study ever conducted in a non-human model: a GWAS of blue eyes based on more than 3,000 customer dogs with validation panels including nearly 3,000 more, the largest canine GWAS to date. We discovered a novel association with blue eyes on chromosome 18 (P = 1.3x10-68) and used both sequence coverage and microarray probe intensity data to identify the putative causal variant: a 98.6-kb duplication directly upstream of the Homeobox gene ALX4, which plays an important role in mammalian eye development. This duplication is largely restricted to Siberian Huskies, is strongly associated with the blue-eyed phenotype (chi-square P = 5.2x10-290), and is highly, but not completely, penetrant. These results underscore the power of consumer-data-driven discovery in non-human species, especially dogs, where there is intense owner interest in the personal genomic information of their pets, a high level of engagement with web-based surveys, and an underlying genetic architecture ideal for mapping studies.


Subject(s)
Dogs/genetics , Eye Color/genetics , Iris Diseases/genetics , Pigmentation Disorders/genetics , Animals , Chromosome Duplication/genetics , DNA , Direct-To-Consumer Screening and Testing , Genome , Genome-Wide Association Study , Genomics/methods , Genotype , Phenotype , Sequence Analysis, DNA
4.
Mol Reprod Dev ; 82(12): 932-56, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26517592

ABSTRACT

Noncoding RNAs (ncRNAs) have long been known to play vital roles in eukaryotic gene regulation. Studies conducted over a decade ago revealed that maturation of spliced, polyadenylated coding mRNA occurs by reactions involving small nuclear RNAs and small nucleolar RNAs; mRNA translation depends on activities mediated by transfer RNAs and ribosomal RNAs, subject to negative regulation by micro RNAs; transcriptional competence of sex chromosomes and some imprinted genes is regulated in cis by ncRNAs that vary by species; and both small-interfering RNAs and piwi-interacting RNAs bound to Argonaute-family proteins regulate post-translational modifications on chromatin and local gene expression states. More recently, gene-regulating noncoding RNAs have been identified, such as long intergenic and long noncoding RNAs (collectively referred to as lncRNAs)--a class totaling more than 100,000 transcripts in humans, which include some of the previously mentioned RNAs that regulate dosage compensation and imprinted gene expression. Here, we provide an overview of lncRNA activities, and then review the role of lncRNAs in processes vital to reproduction, such as germ cell specification, sex determination and gonadogenesis, sex hormone responses, meiosis, gametogenesis, placentation, non-genetic inheritance, and pathologies affecting reproductive tissues. Results from many species are presented to illustrate the evolutionarily conserved processes lncRNAs are involved in.


Subject(s)
Chromatin Assembly and Disassembly/physiology , Chromatin/metabolism , Gene Expression Regulation, Developmental/physiology , Genomic Imprinting/physiology , RNA, Long Noncoding/metabolism , Reproduction/physiology , Animals , Chromatin/genetics , Humans , RNA, Long Noncoding/genetics
5.
PLoS One ; 9(12): e116109, 2014.
Article in English | MEDLINE | ID: mdl-25546018

ABSTRACT

Random X-chromosome inactivation ensures dosage compensation in mammals through the transcriptional silencing of one of the two X chromosomes present in each female cell. Silencing is initiated in the differentiating epiblast of the mouse female embryos through coating of the nascent inactive X chromosome by the non-coding RNA Xist, which subsequently recruits the Polycomb Complex PRC2 leading to histone H3-K27 methylation. Here we examined in mouse ES cells the early steps of the transition from naive ES cells towards epiblast stem cells as a model for inducing X chromosome inactivation in vitro. We show that these conditions efficiently induce random XCI. Importantly, in a transient phase of this differentiation pathway, both X chromosomes are coated with Xist RNA in up to 15% of the XX cells. In an attempt to determine the dynamics of this process, we designed a strategy aimed at visualizing the nascent inactive X-chromosome in live cells. We generated transgenic female XX ES cells expressing the PRC2 component Ezh2 fused to the fluorescent protein Venus. The fluorescent fusion protein was expressed at sub-physiological levels and located in nuclei of ES cells. Upon differentiation of ES cell towards epiblast stem cell fate, Venus-fluorescent territories appearing in interphase nuclei were identified as nascent inactive X chromosomes by their association with Xist RNA. Imaging of Ezh2-Venus for up to 24 hours during the differentiation process showed survival of some cells with two fluorescent domains and a surprising dynamics of the fluorescent territories across cell division and in the course of the differentiation process. Our data reveal a strategy for visualizing the nascent inactive X chromosome and suggests the possibility for a large plasticity of the nascent inactive X chromosome.


Subject(s)
Cell Differentiation/genetics , Embryonic Stem Cells/cytology , Germ Layers/cytology , Imaging, Three-Dimensional , X Chromosome Inactivation/genetics , X Chromosome/genetics , Animals , Cell Nucleus/metabolism , Cell Survival , Enhancer of Zeste Homolog 2 Protein , Female , Interphase , Mice , Mice, Transgenic , Mitosis , Polycomb Repressive Complex 2/metabolism , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism
6.
PLoS One ; 7(7): e39929, 2012.
Article in English | MEDLINE | ID: mdl-22808074

ABSTRACT

Horse body size varies greatly due to intense selection within each breed. American Miniatures are less than one meter tall at the withers while Shires and Percherons can exceed two meters. The genetic basis for this variation is not known. We hypothesize that the breed population structure of the horse should simplify efforts to identify genes controlling size. In support of this, here we show with genome-wide association scans (GWAS) that genetic variation at just four loci can explain the great majority of horse size variation. Unlike humans, which are naturally reproducing and possess many genetic variants with weak effects on size, we show that horses, like other domestic mammals, carry just a small number of size loci with alleles of large effect. Furthermore, three of our horse size loci contain the LCORL, HMGA2 and ZFAT genes that have previously been found to control human height. The LCORL/NCAPG locus is also implicated in cattle growth and HMGA2 is associated with dog size. Extreme size diversification is a hallmark of domestication. Our results in the horse, complemented by the prior work in cattle and dog, serve to pinpoint those very few genes that have played major roles in the rapid evolution of size during domestication.


Subject(s)
Breeding , Genetic Loci , Genetic Variation , Genome , Horses/genetics , Animals , Body Size , Cattle , Cell Cycle Proteins/genetics , Dogs , Female , Genome-Wide Association Study , HMGA2 Protein/genetics , Haplotypes , Humans , Male , Transcription Factors/genetics , Zinc Fingers
7.
Child Abuse Negl ; 35(12): 1002-8, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22050956

ABSTRACT

OBJECTIVES: What impact does the strengthening of child rights have on the experience and circumstances of children? CRC General Comment 13 emphasizes that defining measurable targets for improvements in child protection is a key element of efforts to strengthen child rights and well-being across the world. This paper describes an attempt to identify key domains relevant to such mapping of child protection indicators, and the feasibility of collecting data-from existing data sources or otherwise-to complete a "National Child Protection Index Report" summarizing achievements and concerns at a national level. METHODS: A process of inter-agency consultation was facilitated by the CPC Learning Network to establish a template for the Index Report. The template was modeled on that used for the "Countdown to 2015" maternal, neonatal and child health initiative, aiming to capture indices not only of key protection risks but also implementation and coverage of key protection measures. The work drew on indicator development and policy initiatives by a number of international child protection agencies. The template developed was used as a basis to pilot national data collection in Indonesia and, at a sub-national level, in northern Uganda. FINDINGS: The template provides a concise summary of protection issues of relevance to a broad range of constituencies, global and national. However, in the pilot settings, existing routine data collection was inadequate to effectively populate a large proportion of indicators. Mechanisms of collating findings from discrete assessments-another potential source of data for completion of the index report-were also generally underdeveloped. PRACTICE IMPLICATIONS: In settings where state infrastructure allows the collection and analysis of routine data in such domains as health and economic activity, such efforts should be extended to the child protection sector. Discrete assessments by governmental or non-governmental agencies also provide significant potential for more effective sharing and collation of information. National Child Protection sub-clusters or equivalent structures can play an important role in facilitating both of these processes.


Subject(s)
Child Welfare , Child , Child Advocacy , Data Collection/standards , Global Health , Health Status Indicators , Humans , Indonesia , Uganda , United Nations
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