Transcriptome analyses and differential gene expression in a non-model fish species with alternative mating tactics

Abstract

BackgroundSocial dominance is important for the reproductive success of males in many species. In the black-faced blenny (Tripterygion delaisi) during the reproductive season, some males change color and invest in nest making and defending a territory, whereas others do not change color and ‘sneak’ reproductions when females lay their eggs. Using RNAseq, we profiled differential gene expression between the brains of territorial males, sneaker males, and females to study the molecular signatures of male dimorphism.ResultsWe found that more genes were differentially expressed between the two male phenotypes than between males and females, suggesting that during the reproductive period phenotypic plasticity is a more important factor in differential gene expression than sexual dimorphism. The territorial male overexpresses genes related to synaptic plasticity and the sneaker male overexpresses genes involved in differentiation and development.ConclusionsPreviously suggested candidate genes for social dominance in the context of alternative mating strategies seem to be predominantly species-specific. We present a list of novel genes which are differentially expressed in Tripterygion delaisi. This is the first genome-wide study for a molecular non-model species in the context of alternative mating strategies and provides essential information for further studies investigating the molecular basis of social dominance.

Brain Transcriptional Profiles of Male Alternative Reproductive Tactics and Females in Bluegill Sunfish

“…The total amount of time required for euthanasia, brain dissection, and brain storage in RNAlater was Table 1. Proposed candidate genes (from [18]) influencing teleost alternative reproductive tactics (ARTs). POA = Pre-optic area…”

“…Key enzyme in estrogen biosynthesis é in territorial cichlid males [16]; é territorial blenny males [23]; é territorial black-faced blenny males [18]; ê in the sonic motor nucleus and ventromedial nucleus of nesting type I (territorial) male plainfin midshipman compared to type II (sneaker) males [24, é in territorial cichlid males [16] Somatostatin (sst) Neuropeptide that regulates endocrine pathways. Also affects neurotransmitters é in territorial blenny males [18]; éin territorial cichlid males [16] Early growth response 1 (egr1)…”

“…However, within ARTs, differences in neural expression profiles can often be larger among male tactics than between males and females [18][19][20]. In bluegill, only two transcripts were consistently differentially expressed in females when compared to all male groups and these corresponded to gal and tac.…”

De novo Assembly, Characterization and Functional Annotation of Southern Hake (Merluccius australis) Transcriptome

“…Although N50 is not an exact parameter to measure the accuracy of contigs (Salzberg et al, 2012), it is one of the most popular reference-free measures (Li et al, 2014). The N50 value was in the range reported for other transcriptome de novo fish studies (Milano et al, 2011;Fan et al, 2014;Schunter et al, 2014). …”

A framework for incorporating evolutionary genomics into biodiversity conservation and management

“…At a functional level, genomics approaches can also identify the networks of genes/proteins and their expression profiles required for key adaptations. Whilst once limited in application to model organisms, the technology is now increasingly applicable to non-model species despite ongoing challenges around annotation [49,50]. Below, we briefly outline the various methods for generating and analysing genomic data bearing on biodiversity conservation, their strengths and weaknesses, and then describe how genomic information can explicitly be incorporated into a decision-making framework for biodiversity conservation in the face of climate change.…”