Nucleic acids and protein content in relation to growth and regression of buffalo (Bubalus bubalis) corpora lutea

Information on nucleic acids and protein content of buffalo corpus luteum (CL) in relation to growth, development and regression is not available. An experiment was thus conducted to investigate the variation and relationship between nucleic acids and protein content in CL during different developmental stages and to determine the qualitative differences in protein constituents in any of these stages. Buffalo corpora lutea of different developmental stages viz., developing (day 5-10, n = 16), developed (day 11-17, n = 12) and regressed (day 18-21, n = 10) stages were collected from non-pregnant and -pathological genitalia (n = 38). The DNA, RNA and protein content in tissue extracts were determined and the proteins in pooled samples were analyzed by polyacrylamide gel electrophoresis. Developing stage CL had more total and per gram tissue level of DNA and RNA with significant positive relationship with total and per gram RNA and protein contents. Although there was no significant difference in total weight, a significant decrease in total DNA as well as per gram level of DNA and RNA was observed in developed stage compared to developing stage CL. The total protein content in developed stage CL was compared to developing and regressed stage CL. Non-denaturing PAGE analysis of CL proteins of different stages showed five protein bands of 210, 190, 82, 68 and 66 kDa and one that migrated with the dye front in all the stages however, not shown any differences in banding pattern. Denaturing PAGE showed 15 bands viz., 205, 66, 53, 42, 35, 27, 24, 22, 20, 18, 17, 14, 9, 7.5 and 6.5 kDa. Out of these 66 and 53 kDa bands appeared with maximum intensity in all the three stages of CL. Comparison of bands between the three stages revealed five 57, 31, 27, 19 and 16 kDa stage-specific bands in regressed stage CL. The present study indicated that the DNA, RNA and protein content of buffalo CL varied with the stages of development and regressed stage CL contained some unique protein bands which were not observed either in developed or developing stage CL.