Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: February 22, 1996
Publication Date: N/A
Anterior pituitary gland RNA isolated from sexually mature Meishan and White composite (Chester White, Landrace, Large White and Yorkshire) boars was compared by differential display. This new technique of studying differentially expressed mRNA in comparative samples involves transcription of mRNA with an anchored oligo-dT primer. Subsequently, cDNA is amplified by polymerase chain reaction in the presence of a second short primer of arbitrary sequence that anneals at different regions relative to the first primer. Thyroid-stimulating hormone beta (TSH-beta) subunit gene was found to be more highly expressed in Meishan than in White composite pigs. Cloning of cDNA for TSH-beta subunit gene revealed that the nucleotide sequence is identical between these two breeds but differs from that reported previously for a Japanese pig at the nucleotide positions 75 and 80. RNase protection assay confirmed the results observed from the differential display experiment and showed that expression of TSH-beta subunit gene is significantly greater in Meishan than in White composites (3.12 +/- 1.24 vs. .88 +/- .57; P < .05). Plasma TSH concentration was also significantly greater (P < .01) in mature Meishan males and females (2.34 +/- .06) than in mature White composites (1.98 +/- .06). We propose that such elevated plasma TSH concentrations may contribute to Meishan pigs reaching sexual maturity earlier than White composites or other European breeds. The approach employed in this study could be applied to other animal species or tissues for identification of genes that are differential expressed between individuals, populations or breeds.