Project description:A male zebra finch begins to learn to sing by memorizing a tutor’s song during a sensitive period in juvenile development. Tutor song memorization requires molecular signaling within the auditory forebrain. Using microarray and in situ hybridizations, we tested whether the auditory forebrain at an age just before tutoring expresses a different set of genes compared with later life after song learning has ceased. Microarray analysis revealed differences in expression of thousands of genes in the male auditory forebrain at posthatch day 20 (P20) compared with adulthood. Furthermore, song playbacks had essentially no impact on gene expression in P20 auditory forebrain, but altered expression of hundreds of genes in adults. Most genes that were song-responsive in adults were expressed at constitutively high levels at P20. Using in situ hybridization with a representative sample of 44 probes, we confirmed these effects and found that birds at P20 and P45 were similar in their gene expression patterns. Additionally, eight of the probes showed male–female differences in expression. We conclude that the developing auditory forebrain is in a very different molecular state from the adult, despite its relatively mature gross morphology and electrophysiological responsiveness to song stimuli. Developmental gene expression changes may contribute to fine-tuning of cellular and molecular properties necessary for song learning.
Project description:A male zebra finch begins to learn to sing by memorizing a tutorM-bM-^@M-^Ys song during a sensitive period in juvenile development. Tutor song memorization requires molecular signaling within the auditory forebrain. Using microarray and in situ hybridizations, we tested whether the auditory forebrain at an age just before tutoring expresses a different set of genes compared with later life after song learning has ceased. Microarray analysis revealed differences in expression of thousands of genes in the male auditory forebrain at posthatch day 20 (P20) compared with adulthood. Furthermore, song playbacks had essentially no impact on gene expression in P20 auditory forebrain, but altered expression of hundreds of genes in adults. Most genes that were song-responsive in adults were expressed at constitutively high levels at P20. Using in situ hybridization with a representative sample of 44 probes, we confirmed these effects and found that birds at P20 and P45 were similar in their gene expression patterns. Additionally, eight of the probes showed maleM-bM-^@M-^Sfemale differences in expression. We conclude that the developing auditory forebrain is in a very different molecular state from the adult, despite its relatively mature gross morphology and electrophysiological responsiveness to song stimuli. Developmental gene expression changes may contribute to fine-tuning of cellular and molecular properties necessary for song learning. Post-hatch day 20 male zebra finches that had been raised in acoustic isolation with a foster female or adult male zebra finches were placed in a song playback chamber. The next day, birds heard either silence (control) or 30 minutes of novel song. All samples were hybridized against the universal SoNG RNA reference pool, 6 biological replicates per group in each of 4 groups.
Project description:Social interactions can drive distinct gene expression profiles which may vary by social context. Here we use female sailfin molly fish (Poecilia latipinna) to identify genomic profiles associated with preference behavior in distinct social contexts: male-interactions (mate choice) versus female-interactions (shoaling partner preference). We measured behavior of 15 females interacting in a non-contact environment with either two males or two females for 30 minutes followed by whole brain transcriptomic profiling by RNA sequencing. We profiled females that exhibited high levels of social affiliation and great variation in preference behavior to identify an order of magnitude more differentially expressed genes associated with behavioral variation than by differences in social context. Using linear modeling (limma), we took advantage of the individual variation in preference behavior to identify unique gene sets that exhibited distinct correlational patterns of expression with preference behavior in each social context. By combining limma and weighted gene co-expression network analyses (WGCNA) approaches we identify a refined set of 401 genes robustly associated with mate preference that is independent of shoaling partner preference or general social affiliation. While our refined gene set confirmed neural plasticity pathways involved in moderating female preference behavior, we also identified a significant proportion of discovered that our preference-associated genes were enriched for ‘immune system’ gene ontology categories. We hypothesize that the association between mate preference and transcriptomic immune function is driven by the less well-known role of these genes in neural plasticity which is likely involved in higher-order learning and processing during mate choice decisions.
Project description:The integration of the results of QTL fine-mapping with microarray expression data offers a promising tool for understanding the genetic mechanisms influencing complex traits as fatty acid composition in pigs. The expression level of each probe may be treated as a quantitative trait and the marker genotypes used to map loci with regulatory effect on the gene expression level (eQTL) According to our previous linkage results, we carry out an eQTL scan focused on chromosomal regions showing tissue-consistent effects on fatty acids with Longissimus dorsi gene expression data in order to detect potentional candidate genes underlying the QTL previously detected.
Project description:Simple Markov model.
There are 3 disease states: Healthy, Sick, and Dead, where the Dead state is terminal.
The yearly transition probabilities are:
Healthy to Dead: 0.01; Healthy to Sick: 0.2 for Male and 0.1 for Female; Sick to Healthy: 0.1; Sick to Dead: 0.3.
The transition probability now depends on the cohort (Male or Female) and can be expressed as a function of a Boolean covariate Male.
Initial conditions: Healthy = (50 Male, 50 Female), Sick = (0,0) and Dead = (0,0).
Output: Number of men and women in each disease state for years 1-10.
Project description:How evolutionary changes in genes and neurons encode species variation in complex motor behaviors are largely unknown. Here, we develop genetic tools that permit a neural circuit comparison between the model speciesDrosophila melanogasterand the closely-related speciesD. yakuba, who has undergone a lineage-specific loss of sine song, one of the two major types of male courtship song inDrosophila. Neuroanatomical comparison of song patterning neurons called TN1 across the phylogeny demonstrates a link between the loss of sine song and a reduction both in the number of TN1 neurons and the neurites serving the sine circuit connectivity. Optogenetic activation confirms that TN1 neurons inD. yakubahave lost the ability to drive sine song, while maintaining the ability to drive the singing wing posture. Single-cell transcriptomic comparison shows thatD. yakubaspecifically lacks a cell type corresponding to TN1A neurons, the TN1 subtype that is essential for sine song. Genetic and developmental manipulation reveals a functional divergence of the sex determination genedoublesexinD. yakubato reduce TN1 number by promoting apoptosis. Our work illustrates the contribution of motor patterning circuits and cell type changes in behavioral evolution, and uncovers the evolutionary lability of sex determination genes to reconfigure the cellular makeup of neural circuits.
Project description:Sexual selection involves mate preference behavior and is a critical determinant for natural selection and evolutionary biology. Previously an environmental compound (fungicide vinclozolin) was found to promote epigenetic transgenerational inheritance of modified mate selection characteristics in all progeny for three generations after exposure of a gestating female. The current study investigated gene networks involved in various regions of the brain that correlated with the mate preference behavior altered in F3-Vinclozolin lineage animals. Statistically significant correlations of differentially expressed gene clusters and modules were identified to associate with specific mate preference behaviors. This novel systems biology approach identified critical gene networks involved in mate preference behavior and demonstrated the ability of environmental factors to promote epigenetic transgenerational inheritance of this altered evolutionary biology determinant. Combined observations elucidate the potential molecular control of mate preference behavior and suggests environmental epigenetics can have a role in evolutionary biology. We used Affymetrix Rat Gene 1.0 ST microarrays to determine genes expressed differentially in F3 Vinclozolin lineage male or female rats' 6 brain areas - amygdala (Amy), hippocampus (Hipp), olfactory bulb (OlfB), cingulate cortex (CngCtx), entorhinal cortex (EnCtx), and preoptic area-anterior hypothalamus (POAH) - due to Vinclozolin treatments of their grand-grandmothers (F0). For each of 6 brain areas of male or female rats (female: amygdala (F-Amy), cingulate cortex (F-CngCTX), enterorhinal cortex (F-EnCTX), hippocampus (F-Hipp), olfactory bulbs (F-OlfB), and preoptic area-anterior hypothalamus (F-POAH); male: amygdala (M-Amy), cingulate cortex (M-CngCTX), enterorhinal cortex (M-EnCTX), hippocampus (M-Hipp), olfactory bulbs (M-OlfB), and preoptic area-anterior hypothalamus (M-POAH)), RNA samples from 2 treatment groups - F3 Control lineage (Con) or F3 Vinclozolin lineage (Vin) - were compared to each other. Each of treatment groups contained 4-6 biological replicas for each brain region. RNA for each replica was isolated from an individual animal in order to compare to individual animal mate preference behavior studied with the same rats before sacrifice. Totally, 132 RNA samples from 24 animals (6 male F3 Control, 6 male F3 Vinclozolin,6 female F3 Control, and 6 female F3 Vinclozolin) were isolated and studied.
Project description:A number of genes associated with sexual traits and reproduction evolve at the sequence level faster than the majority of genes coding for non-sex-related traits. Whole genome analyses allow this observation to be extended beyond the limited set of genes that have been studied thus far. We use cDNA microarrays to demonstrate that this pattern holds in Drosophila for the phenotype of gene expression as well, but in one sex only. Genes that are male-biased in their expression show more variation in relative expression levels between conspecific populations and two closely related species than do female-biased genes or genes with sexually monomorphic expression patterns. Additionally, elevated ratios of interspecific expression divergence to intraspecific expression variation among male-biased genes suggest that differences in rates of evolution may be due in part to natural selection. This finding has implications for our understanding of the importance of sexual dimorphism for speciation and rates of phenotypic evolution. Keywords: other