Abstract #M129

# M129
Transcriptome profiling of pituitary gland from pre- and post-pubertal beef heifers.
Robmay Garcia*1, Dianelys Gonzalez-Pena1, Bruce R. Southey1, Sandra L. Rodriguez-Zas1, 1University of Illinois at Urbana Champaign, Urbana, IL.

Onset of puberty is a key component of animal production and reproductive efficiency. The pituitary gland plays a major role in reproductive readiness. A comprehensive understanding of the associated transcriptome changes during peripuberty will aid in the development of treatments and management practices to improve reproductive performance. The objective of this study was to gain understanding of the transcriptome associated with changes pre- and post-puberty. The transcriptome of pituitary tissue from 4 pre-pubertal beef heifers was compared with that of 4 different post-pubertal beef heifers using individual RNA-seq libraries. Single-end reads were mapped to the Bos taurus reference genome (Btau_4.6.1) using Tophat v2.0.12. In total, 10,489 isoform transcripts pertaining to 10,234 genes were identified and 1,162 isoform transcripts pertaining to 1,149 genes were differentially expressed between post-puberty and pre-puberty pituitary tissue (False Discovery Rate-adjusted P-value <0.05) using Cufflinks v2.2.1. Among the most relevant and significant (false discovery rate adjusted P-value <0.03) genes associated with reproductive maturation were leptin receptor (LEPR) and vasoactive intestinal peptide (VIP), and endothelin 1 (EDN1). Increments in leptin receptors encoded by LEPR are associated with gonad maturation, the advent of reproductive maturity and fertility. VIP encodes the VIP neuropeptide that among other roles, participates in ovarian development and stimulation of prolactin release under the influence of estrogen. EDN1 encodes the EDN1 neuropeptide that is involved in mechanisms controlling the gonadotropins and prolactin secretion, also inhibiting synthesis of progesterone and premature luteinization of granulosa cells. Functional analysis of the differentially expressed genes using DAVID identified 4 enriched functional category clusters (enrichment score >2): blood vessels and vasculature development, collagen fibrin and extracellular organization, carbohydrate and hyaluronic acid binding, and transforming growth factor β receptor signaling pathway. These categories confirm a wide range of changes associated with beef heifers transitioning from pre- to post-puberty and suggest potential pharmacological targets.

Key Words: transcriptome, puberty, pituitary