You are here:
SPERM MOTILITY IN HSF1 KNOCKOUT MICE AFTER HEAT SHOCK IS ASSOCIATED WITH FERTILITY DEFICITS
Citation:
Strader, L F., S P. Darney, J. C. Luft, AND D J. Dix. SPERM MOTILITY IN HSF1 KNOCKOUT MICE AFTER HEAT SHOCK IS ASSOCIATED WITH FERTILITY DEFICITS. Presented at American Society of Andrology, Seattle, WA, April 24-28, 2002.
Description:
SPERM MOTILITY IN HSF1 KNOCKOUT MICE AFTER HEAT SHOCK IS ASSOCIATED WITH FERTILITY DEFICITS. L.F. Strader*, S.D. Perreault, J.C. Luft*, and D.J. Dix*. US EPA/ORD, Reproductive Toxicology Div., Research Triangle Park, NC
Heat shock proteins (HSPs) protect cells from environmental exposures such as hyperthermia, oxygen radicals, and heavy metals. During the stress response in mouse testis, expression of inducible HSPs is regulated by activation of heat shock factor 1 (Hsf1). We hypothesized that Hsf1 gene knockout (KO) mice would be more susceptible than wild type (WT) to hyperthermia. Adult WT and KO males were exposed to 25 degrees C (control) or 43 degrees C (heat shock) for 20 minutes. Males were bred from 3-4 weeks after treatment to confirm fertility deficits in response to hyperthermia, and again from 12-13 weeks to examine recovery in WT and KO mice. Results of the first breeding period showed significant reduction in the number of litters for WT, and no litters for KO males exposed to heat. By 12 weeks the number of litters did not differ between heat shocked and control WT, while heat shocked KO mice continued to be significantly different. Sixteen weeks after treatment males were sacrificed for organ weights, histology, and epididymal sperm motility using CASA (Hamilton Thorne IVOS, version 12.0L). Sperm were tracked for 1 sec (60 frames/sec) with a minimum track length of 30 frames. Progressive sperm were defined by setting average path velocity (VAP)=80 and Straightness=50. CASA parameters were similar for WT males, both control and heat shock, indicating recovery of sperm motility. In contrast, Hsf1 KO males exhibited significant decrements in percent motile and percent progressive sperm, and mean VAP, straight line velocity, curvilinear velocity, straightness, and linearity - indicating a lack of recovery following heat shock. Thus sperm motility data could explain differences in breeding performance between WT and Hsf1 KO mice. This abstract does not reflect EPA Policy.