Prairie View A&M University
Fertility phenotypes traditionally show low heritability. This makes fertility-related selection practices impractical in livestock species. Semen analysis parameters alone are insufficient to determine fertility status of individual animals. Despite stringent semen analyses in Artificial Insemination (AI) programs, measures of fertilizability are often incongruent with measures of sperm ability to undergo capacitation, fuse with the egg membrane, and de-condense the sperm head within the cytoplasm of the oocyte. The use of RNA-Seq as a tool to identify molecular biomarkers for fertility presents an appealing method to increase the efficiency of artificial insemination and embryo transfer in goats.
The RNA-Seq data generated herein is the first step in a multiphase project that will associate testes, sperm, and seminal plasma molecular signatures with measures of potential fertility; the genotypic and phenotypic data here will lead to the development diagnostic biomarkers for the fertility status of individual animals. Our overarching hypothesis is that distinct mRNA expression profiles in testes, mature haploid spermatozoa, and seminal plasma will show correlations between juvenile development, and during the pathogenesis of infertility and recovery. Genes important for the acquisition of normal testes function during juvenile development to puberty may also show distinct expression profiles during the pathogenesis of poor semen quality and recovery.
Ongoing research projects are focused on the characterization of mRNA and small non-coding RNA (small ncRNA) expression in spermatozoa (intracellular RNA – inRNA) and in seminal plasma (secreted extracellular RNA – exRNA) during the pathogenesis of heat-induced poor semen quality and recovery in goats. The integration of RNA-Seq data from spermatozoa, seminal plasma, and testes will allow undergraduate students to develop animal breeding programs that incorporate molecular biomarkers for potential fertility in juvenile or adult animals.
By training the next generation of agricultural scientists, and ensuring our students are competitive and prepared for the demands of a new cross-discipline integration of STEM-related fields driven by technological advances, the infrastructure and training in NGS analysis will expose undergraduate students in Agriculture, Biology, Chemistry, and Engineering at PVAMU to a mentored, research-based training in agricultural biotechnology.
The primary functions of the testis are (1) synthesis and secretion of testosterone and (2) spermatogenesis. These functions are acquired sequentially during normal fetal, neonatal, and juvenile testis development to puberty, which defines the completion of functional acquisition. Male Alpine goats were castrated to collect testes tissue (parenchyma) from 0, 2, 4, and 6-month postnatal time points (n ≥ 5 animal/time point). For each animal, the testicles were dissected to isolate the parenchyma, snap frozen and used for RNA extraction and generation of Illumina RNA-Seq libraries.
RNA-Seq data sets comparing genes expressed in testis parenchyma during neonatal to juvenile development will be made available at a time to be determined. Real-time qPCR data of candidate genes significantly up or down regulated and involved in testis development or function.
SRA data from caprine, ovine and bovine species focused on the application of RNA-Seq as a tool to understand the development and function of the testis.
I teach an upper level, one-semester animal-breeding course that does not have a lab component. Students in my class will focus on the analysis, interpretation, and integration of NGS sequencing data into herd management, breeding, and selection practices.
Materials are under development.