Expression of Heat Shock Proteins by Isolated Mouse Spermatogenic Cells

Abstract

Proteins of the hsp70 family are abundant in mouse spermatogenic cells. These cells also synthesize relatively large amounts of a 70,000-molecular-weight protein (P70) that appears to be a cell-specific isoform of hsp70, the major heat-inducible protein (R.L. Allen, D.A. O'Brien, and E.M. Eddy, Mol. Cell. Biol. 8:828-832, 1988). In this study, proteins of unstressed and heat-stressed spermatogenic cells consisting of purified preparations of preleptotene, leptotene-zygotene, pachytene spermatocytes, and round spermatids were analyzed by two-dimensional polyacrylamide gel electrophoresis. Unstressed preleptotene and leptotene-zygotene spermatocytes contained little P70, whereas relatively large amounts of P70 were present in pachytene spermatocytes and round spermatids. Labeling studies showed that P70 was synthesized primarily in pachytene spermatocytes and that little synthesis occurred in round spermatids or in preleptotene and leptotene-zygotene stages of spermatogenesis. Synthesis of hsp70 was not detectable in unstressed cells but was induced in all stages of isolated germ cells following heat stress. These results indicate that P70 is expressed in a stage-specific manner during cell differentiation, whereas hsp70 is synthesized in response to stress in all populations of isolated spermatogenic cells examined.

Association between HSP70 Genotypes and Oocytes Development on In vitro Maturation/Fertilization in Pig

“…Important factors determining the success of porcine in vitro fertilization are maturity of follicular oocytes, sperm activity and concentration, and temperature changes (Mattioli et al, 1991;Kikuchi et al, 1993). Allen et al (1988) and Zakeri et al (1990) have reported that several HSP genes mediate great effects on the development of normal reproductive cells. Neuer et al (1999) have reported that high sensitivity of oocytes was associated with the reaction of HSP70 gene express during the meiosis maturation, and it is the key molecules for the protection of cells from heat shock and stress (Ananthan et al, 1986;Lindquist, 1986;Welch, 1992;Hansen, 1999).…”

“…Porcine HSP reacts on cell growth substantially under stressful conditions caused by the change of temperature, particularly, in response to sudden elevation of the external temperature, HSP is very important for the maintenance of the cell viability of fetus or neonates (Dezeure et al, 1993;Lindquist, 1986). Although its importance on the protection of reproductive cells from temperature stress has not been elucidated yet, several HSP gene groups have been reported to mediate great effects on the development of normal reproductive cells (Allen et al, 1988;Zakeri et al, 1990). HSP70 gene is involved in proteins secreted by rising and dropping temperature, and pigs which were inherited DNA variation of physiological in adaptability to temperature changes are speculated to cause the deterioration of the productibility and breeding capacity of pigs (Huang et al, 2000(Huang et al, , 2002.…”