Project description:The black-footed ferret (Mustela nigripes) is a star example of the efforts of conservation programs in bringing endangered species back from the brink of extinction. As one of the world’s most endangered mammals, the vast majority of black-footed ferrets living in the wild today are the offspring of a founding captive population. The success of this ongoing breeding program, however, is threatened by inbreeding depression and the observed decline in pregnancy rates since its founding. As the wild and modern captive populations share a genetic history, the greatest difference between the two groups is the captive environment of the breeding program. In this study, we used RNA sequencing and proteomics for the first time in black-footed ferrets to explore whether the diet of wild ferrets versus captive diet variants could explain the differences in fertility and sperm characteristics observed between each population. We find that changes in both the transcriptional and proteomic profile of black-footed ferret ejaculate are strongly associated with differences in fertility, especially in pathways associated with innate immunity and metabolism; that transcriptional changes are further exacerbated by diet. Overall, our results support the hypothesis of ongoing environmental-dependent inbreeding depression in the black-footed ferret, with a need to re-evaluate dietary and environmental parameters of the conservation program; and also illustrates the value of multi-level genomics for conservation management programs.
Project description:The Malayan pangolin (Manis javanica), an unusual mammal that is a scale-covered, toothless specialist myrmecophage, is maintained primarily through captive breeding in China. Maintaining this species in captivity is a significant challenge partly because little is known about its behavior and reproduction. The molecular mechanisms of its digestive system play a key role in the feeding and dietary husbandry of pangolins in captivity. Here, we performed the first large-scale sequencing of M. javanica transcriptomes from three digestive organs—the salivary glands, liver, and small intestine—by using Illumina HiSeq technology- to provides useful genetic resources for future functional work that may be relevant for the maintenance of captive pangolins.
Project description:We investigated whether exposure to a captive environment during maturation influenced gamete DNA methylation for wild Atlantic Salmon individuals. We then investigated whether these parental effects were detectable in an F1 generation reared in a common environment. We associated DNA methylation with growth and fitness-related phenotypes and demonstrated that intergenerational effects of hatchery exposure during maturation of the parental generation influence fitness-related methylation patterns in the F1 generation.
2020-11-26 | GSE162129 | GEO
Project description:Captive breeding Pangolin gut virus
Project description:Male zebra finches of a captive population in the University of Sheffield were artificially selected for long or short sperm based on their breeding values for three generations. We used Affymetrix microarrays to examine gene expression differences between testes of selection line male birds.
Project description:Gene expression heterogeneity is ubiquitous within single cell datasets, even among cells of the same type. Heritable expression differences, defined here as those which persist over multiple cell divisions, are of particular interest, as they can underlie processes including cell differentiation during development as well as the clonal selection of drug-resistant cancer cells. However, heritable sources of variation are difficult to disentangle from non-heritable ones, such as cell cycle stage, asynchronous transcription, and measurement noise. Since heritable states should be shared by lineally related cells, we sought to leverage CRISPR-based lineage tracing, together with single cell molecular profiling, to discriminate between heritable and non-heritable variation in gene expression. We show that high efficiency capture of lineage profiles alongside single cell gene expression enables accurate lineage tree reconstruction and reveals an abundance of progressive, heritable gene expression changes. We find that a subset of these are likely mediated by structural genetic variation (copy number alterations, translocations), but that the stable attributes of others cannot be understood with expression data alone. Towards addressing this, we develop a method to capture cell lineage histories alongside single cell chromatin accessibility profiles, such that expression and chromatin accessibility of closely related cells can be linked via their lineage histories. We call this then leverage this indirect “coassay” approach "THE LORAX" and leverage it to explore the genetic and epigenetic mechanisms underlying heritable gene expression changes. Using this approach, we show that we can discern between heritable gene expression differences mediated by large and small copy number changes, trans effects, and possible epigenetic variation.
Project description:Advancements in -omics techniques provide powerful tools to assess potential effects in composition of a plant at the RNA, protein and metabolite levels. These technologies can thus be deployed to assess whether genetic engineering causes changes in plants that go beyond the changes introduced by conventionally plant breeding. Here, we compare the extent of transcriptome and metabolome modification occurring in leaves of four GE rice lines expressing Bacillus thuringiensis (Bt) genes that developed by genetic engineering and seven rice lines developed by conventional cross-breeding. The results showed that both types of crop breeding methods can bring changes at transcriptomic and metabolic levels, but the differences were comparable between the two methods, and were less than those between conventional non-GE lines. Metabolome profiling analysis found several new metabolites in GE rice lines when compared to the closest non-GE parental lines, but these compounds were also found in several of the conventionally bred rice lines. Functional analyses suggest that the differentially expressed genes and metabolites caused by both genetic engineering and conventional cross-breeding do not involve detrimental metabolic pathways. The study successfully employed RNA-sequencing and HPLC-MS technology to assess the unintended changes in new rice varieties, and the results suggest that genetic engineering does not cause unintended effects that go beyond conventional cross-breeding in rice.
Project description:Background: Aquaculture of the black tiger prawn Penaeus monodon remains severely constrained by an almost total dependence on wild-caught broodstock. Reliance on wild-caught broodstock stems, for the most part, from reduced reproductive potential of captive-reared females. Reproductive performance of captive-reared females is usually characterised by longer latency period, lower egg production, egg hatch rates and post-larval survivorship compared with their wild-caught counterparts. Improved understanding of the cellular and associated molecular events occurring during peneaid ovarian maturation could therefore be fundamental to improving reproductive success of captive-reared animals. Methodology/Principle Findings: In support of other studies, our histological analyses of developing oocytes revealed differences between wild-caught and captive-reared P. monodon, including reduced lipid accumulation in oocytes of captive-reared animals. We have employed oligonucleotide microarray analysis to compare expression profiles of genes involved in ovarian maturation among wild-caught and captive-reared animals. Custom oligonucleotide microarrays were constructed and screened with transcripts derived from the ovary, cephalothorax and eyestalk from animals of all ovarian maturation stages. Ovarian maturation-related differential expression patterns were observed for 111 transcripts, with 53 transcripts displaying differential expression between wild-caught and captive-reared animals. Notably transcripts encoding vitellogenin - the major egg yolk protein precursor, and a lipid storage droplet protein (which we named pmLSD) which is involved in lipid accumulation, were found to be more highly expressed in wild-caught animals. pmLSD transcripts localise to pre-vitellogenic oocytes of wild-caught animals and the pmLSD protein is exclusively localised to the surface of lipid droplets of oocytes at vitellogenic and cortical rod stages. We have employed oligonucleotide microarray analysis to compare expression profiles of genes involved in ovarian maturation among wild-caught and captive-reared animals. Target preparation and microarray hybridisation. Ovarian RNA samples from nine wild-caught animals representing six ovarian maturation stages (P, 2, 24, V, R, E) were used in microarray hybridisations. Similarly, RNA samples from three captive-reared animals representing four maturation stages (P, 24, V, E) were used in microarray hybridisations. For wild-caught animals, samples from each ovarian maturation stage were pooled into groups of four and five, enabling two hybridisations. For captive-reared animals, samples from each ovarian maturation stage from all three animals were pooled enabling one hybridisation for each stage. Importantly, as the four stages for captive-reared animals were (1) pre-ablation pre-vitellogenic, (2) post-ablation pre-vitellogenic, (3) post-ablation vitellogenic, (4) post-ablation vitellogenic with cortical rods, this arrangement allowed for 2 samples of captive-reared pre-vitellogenic and 2 samples of captive-reared vitellogenic, thereby enabling t-tests between samples, while also allowing analysis across the whole 4 stages via cluster analysis. All hybridisations were single channel hybridisations conducted using equal amounts of RNA pooled from each individual.
Project description:Some epigenetic modifications are inherited from one generation to the next, providing a potential mechanism for the inheritance of environmentally acquired traits. Transgenerational inheritance of RNA interference phenotypes in C. elegans provides an excellent model to study this phenomenon, and whilst studies have implicated both chromatin modifications and small RNA pathways in heritable silencing their relative contributions remain unclear. Here we demonstrate that the histone methyltransferases SET-25 and SET-32 are required for the establishment of a transgenerational silencing signal, but not for long-term maintenance of this signal between subsequent generations suggesting that transgenerational epigenetic inheritance is a multi-step process, with distinct genetic requirements for establishment and maintenance of heritable silencing. Furthermore, small RNA sequencing reveals that the abundance of secondary siRNA (thought to be the effector molecules of heritable silencing) does not correlate with silencing phenotypes. Together, our results suggest that the current mechanistic models of epigenetic inheritance are incomplete.
Project description:We sequenced polyA-selected RNA from bone marrow derived cells from 47 bone samples collected from 16 captive, adult female Damaraland mole-rats (Fukomys damarensis). The 16 females were experimentally manipulated to either remain as nonbreeders (either as helpers or solitaires) or become breeders, and breeding status was maintained for over 1 year prior to tissue collection and cell culture. A subset of cultured cells were treated for 24 hours with 10 nM estradiol prior to sample collection.