Degree Type

Dissertation

Date of Award

1996

Degree Name

Doctor of Philosophy

Department

Genetics, Development and Cell Biology

First Advisor

Carol D. Jacobson

Abstract

This dissertation describes the immunohistochemical localization of three neuropeptides in the brain of the male Meishan pig throughout prenatal and prepubertal development;The first study details the ontogeny of neuropeptide Y (NPY) in the male Meishan pig brain. Neuropeptide Y-like immunoreactivity (NPY-IR) was seen in cell bodies and fibers throughout the brain from gestational day (g)30 through postnatal day (pn)50. Cell bodies and fibers containing NPY-IR generally increase in number and distribution in the brain prenatally. However, immunoreactive cell bodies decline in the early postnatal period, especially in the arcuate nucleus of the hypothalamus. This may indicate a functional maturation of food intake control pathways;The second study describes the prepubertal ontogeny of galanin-like immunoreactivity (GAL-IR). Galanin-IR in cell bodies and fibers was evident in the brain at all ages, especially in the hypothalamus. Throughout prenatal development cell bodies and fibers containing GAL-IR generally increased in number and distribution in the brain showing a pattern by pn1 that was consistent through postnatal ages;The third study investigated the prepubertal ontogeny of luteinizing hormone-releasing hormone-like immunoreactivity (LHRH-IR) in the telencephalon and diencephalon. Luteinizing hormone-releasing hormone-IR in cell bodies and fibers was detected at g30 entering the brain along the terminal nerve and in the basal telencephalon. The number of immunoreactive cells increased and immunoreactive fibers were present in the median eminence at g50. Further increases were seen prenatally, but changed little postnatally. These results confirm the olfactory origin of LHRH cells in the pig and suggest a breed difference in the ontogeny of reproductive control systems in the pig;The temporal and neuroanatomical relationship of these peptides suggest that they play important roles in the control of food intake, growth and reproduction in the Meishan pig, a Chinese breed known for its superior reproductive characteristics but slow growth and obesity. Future studies will investigate the interrelationships of these peptides with respect to the control of gonadotropic and somatotropic processes in the pig.

DOI

https://doi.org/10.31274/rtd-180813-10233

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Paul Lyle Pearson

Language

en

Proquest ID

AAI9620983

File Format

application/pdf

File Size

220 pages

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