About

Sex Determination and Differences

I am using genomic approaches to identify novel sex determination genes, and explore how sex chromosomes and autosomes evolve in cichlids. With a thousand species arising within the past two million years or so, African cichlids may represent the most rapidly evolving group of vertebrates on the planet. These fish have incredible phenotypic diversity in a number of traits, including morphology, pigmentation, vision, behavior, sex determination, and gastrointestinal biology - providing a vast array of adaptive phenotypic differences for analysis. Historically, genetic sex determination research has largely focused on a handful of single-factor, chromosomal sex determination systems. More recently, genetic sex determination has been mapped more broadly, revealing a broader set of sex determination genes in a variety of chromosomal contexts. Polygenic sex determination (PSD) has been confirmed in multiple taxa, where multiple genetic factors direct sexual development. While individuals of a species with PSD develop phenotypically as either male or female, several genetic types of males and females may exist. PSD was recently recently identified in Astatotilapia burtoni, with multiple alleles at multiple loci determining sex.

Using a combination of genetic mapping and comparative genomics, we hope to identify the genes involved, provide some understanding of how multiple genetic sex switches are integrated, and characterize the relative evolutionary trajectories of the multiple young sex chromosomes, all in a single species. Our central hypothesis is that several distinct genetic sex determination switch alleles interact in a reproducible manner to direct primary and secondary sexual development. We are working to characterize novel sex determination loci, while producing important genome resources for A. burtoni, a longstanding model for neural and behavioral biology.

Behavior Genetics: Studying Fish and Their Nucleic Acids

My ongoing work in salmonids both rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis), focuses on genetic associations of behavioral and life history variation. I have designed and executed experiments consisting of extensive fieldwork in Alaska and sample collection along the northern coast of Lake Superior in Canada. Within rainbow trout, I am assessing both within and between individual behavioral variation, as well testing whether life history type was associated with certain behaviors (e.g. aggression, exploration, dispersal). I am also interested in evaluating if these behaviors were interconnected and would be part of trade-offs, for example in the context of hatchery rearing or conservation. Some of this work has been published in "Rainbow Trout Personality: Individual Behavioral Variation in Juvenile Rainbow Trout, Oncorhynchus mykiss"(Behaviour 155:205-230). 

I have also tested for correlations between the ecologically relevant behaviors I analyzed and the gene expression in the brain using Illumina RNAseq (verified with qPCR). Using brook trout native to Lake Superior, I tested for genomic regions associated with migratory and resident ecotypes, using next generation sequencing (RAD-tag Illumina) and association mapping. The markers generated were also used to evaluate population structure across a geographic range. This work was published in "Population structure and genomic variation of ecological life history diversity in wild-caught Lake Superior brook trout, Salvelinus fontinalis" (Journal of Great Lakes Research 44:6).

Prental Care & Other Reproductive Behaviors

My previous research primarily focused on parental care in fish. In Finland, I conducted an experiment examining the effect of an egg predator on filial cannibalism in the sand goby (Pomatoschistus minutus), which was published in “Should you eat your offspring before someone else does? Effect of an egg predator on filial cannibalism in the sand goby” (Animal Behaviour 78:203-208). While conducting this experiment, I also assisted in another experiment assessing the effect of general intrasexual resource competition on sexual selection. At the University of Florida, I gathered data for an experiment examining the effect of short and long term experiences, in the form of feeding quality and schedule, on reproductive behavior in the flagfish (Jordanella floridae).

Project Name

Lorem ipsum dolor sit amet, consectetur adipisicing elit. Quos modi in tenetur vero voluptatum sapiente dolores eligendi nemo iste ea. Omnis, odio enim sint quam dolorum dolorem. Nostrum, minus, ad.

• Client: Start Bootstrap
• Date: April 2017
• Service: Web Development