Project description:Cryptorchidism and scrotal heating result in abnormal spermatogenesis but the mechanism(s) proscribing this temperature sensitivity are unknown. It was previously reported that the AKR/N or MRL/MpJ-+/+ mouse testis is more heat resistant than the testis from the C57BL/6 strain. We have attempted to probe into the mechanism(s) involved in heat sensitivity by examining global gene expression profiles of normal and heat-treated testes from C57BL/6, AKR/N and MRL/MpJ-+/+ mice by microarray analysis. In the normal C57BL/6 testis, 415 and 416 transcripts were differentially expressed (at least two-fold higher or lower) when compared to the normal AKR/N and MRL/MpJ-+/+ testis, respectively. The AKR/N and MRL/MpJ-+/+ strains revealed 268 differentially expressed transcripts between them. There were 231 transcripts differentially expressed between C57BL/6 and two purported heat-resistant strains, AKR/N and MRL/MpJ-+/+. Next, the testes of C57BL/6 and AKR/N mice were exposed to 43ºC for 15 min and harvested at different time points for TUNEL studies and microarrays. An increase of TUNEL-positive germ cell numbers was significant 8 hr after heat exposure in the C57BL/6 mouse. However, this increase was not observed in the AKR/N mouse until 10 hr after heat exposure. All tubules showed germ cell loss and disruption in C57BL/6 testis 24 hr after heat shock. In contrast, although a number of seminiferous tubules showed an abnormal morphology 24 hr post-heat shock in the AKR/N mouse, many tubules still retained a normal structure. Numerous transcripts exhibited differential regulation between the two strains within 24 hours after heat exposure. The differentially expressed transcripts in the testes 8 hr after heat exposure were targeted to identify the genes involved in the initial response rather than those due to germ cell loss. Twenty transcripts were significantly down-regulated and 19 genes were up-regulated by hyperthermia in C57BL/6 and did not show a parallel change in the AKR/N testis. Conversely, heat shock resulted in 30 up-regulated transcripts and 31 down-regulated transcripts in AKR/N that were not similarly regulated in C57BL/6. A number of genes shared similar differential expression patterns and differential regulation by hyperthermia in both strains of mice. Taken together, the present study indicates the diverse genetic backgrounds in the three strains lead to major differences in normal testis gene expression profiles while the differences in heat shock responses involves a significantly smaller number of genes. The data generated may provide insights regarding gene networks and pathways involved in heat stress and their relationship to spermatogenesis.
Project description:Cryptorchidism and scrotal heating result in abnormal spermatogenesis but the mechanism(s) proscribing this temperature sensitivity are unknown. It was previously reported that the AKR/N or MRL/MpJ-+/+ mouse testis is more heat resistant than the testis from the C57BL/6 strain. We have attempted to probe into the mechanism(s) involved in heat sensitivity by examining global gene expression profiles of normal and heat-treated testes from C57BL/6, AKR/N and MRL/MpJ-+/+ mice by microarray analysis. In the normal C57BL/6 testis, 415 and 416 transcripts were differentially expressed (at least two-fold higher or lower) when compared to the normal AKR/N and MRL/MpJ-+/+ testis, respectively. The AKR/N and MRL/MpJ-+/+ strains revealed 268 differentially expressed transcripts between them. There were 231 transcripts differentially expressed between C57BL/6 and two purported heat-resistant strains, AKR/N and MRL/MpJ-+/+. Next, the testes of C57BL/6 and AKR/N mice were exposed to 43ºC for 15 min and harvested at different time points for TUNEL studies and microarrays. An increase of TUNEL-positive germ cell numbers was significant 8 hr after heat exposure in the C57BL/6 mouse. However, this increase was not observed in the AKR/N mouse until 10 hr after heat exposure. All tubules showed germ cell loss and disruption in C57BL/6 testis 24 hr after heat shock. In contrast, although a number of seminiferous tubules showed an abnormal morphology 24 hr post-heat shock in the AKR/N mouse, many tubules still retained a normal structure. Numerous transcripts exhibited differential regulation between the two strains within 24 hours after heat exposure. The differentially expressed transcripts in the testes 8 hr after heat exposure were targeted to identify the genes involved in the initial response rather than those due to germ cell loss. Twenty transcripts were significantly down-regulated and 19 genes were up-regulated by hyperthermia in C57BL/6 and did not show a parallel change in the AKR/N testis. Conversely, heat shock resulted in 30 up-regulated transcripts and 31 down-regulated transcripts in AKR/N that were not similarly regulated in C57BL/6. A number of genes shared similar differential expression patterns and differential regulation by hyperthermia in both strains of mice. Taken together, the present study indicates the diverse genetic backgrounds in the three strains lead to major differences in normal testis gene expression profiles while the differences in heat shock responses involves a significantly smaller number of genes. The data generated may provide insights regarding gene networks and pathways involved in heat stress and their relationship to spermatogenesis. Experiment Overall Design: Total RNA of testes from two different strains of mice, C57BL/6 and AKR/N were analyzed using microarray 430.20 chip. Duplicates were used in controls and treated samples at 8hr, 10hr, 12hr, 24hr after heat shock at 43C for 15 min. All mice were 8 weeks old.
Project description:Cryptorchidism and scrotal heating result in abnormal spermatogenesis but the mechanism(s) proscribing this temperature sensitivity are unknown. It was previously reported that the AKR/N or MRL/MpJ-+/+ mouse testis is more heat resistant than the testis from the C57BL/6 strain. We have attempted to probe into the mechanism(s) involved in heat sensitivity by examining global gene expression profiles of normal and heat-treated testes from C57BL/6, AKR/N and MRL/MpJ-+/+ mice by microarray analysis. In the normal C57BL/6 testis, 415 and 416 transcripts were differentially expressed (at least two-fold higher or lower) when compared to the normal AKR/N and MRL/MpJ-+/+ testis, respectively. The AKR/N and MRL/MpJ-+/+ strains revealed 268 differentially expressed transcripts between them. There were 231 transcripts differentially expressed between C57BL/6 and two purported heat-resistant strains, AKR/N and MRL/MpJ-+/+.
Project description:Cryptorchidism and scrotal heating result in abnormal spermatogenesis but the mechanism(s) proscribing this temperature sensitivity are unknown. It was previously reported that the AKR/N or MRL/MpJ-+/+ mouse testis is more heat resistant than the testis from the C57BL/6 strain. We have attempted to probe into the mechanism(s) involved in heat sensitivity by examining global gene expression profiles of normal and heat-treated testes from C57BL/6, AKR/N and MRL/MpJ-+/+ mice by microarray analysis. In the normal C57BL/6 testis, 415 and 416 transcripts were differentially expressed (at least two-fold higher or lower) when compared to the normal AKR/N and MRL/MpJ-+/+ testis, respectively. The AKR/N and MRL/MpJ-+/+ strains revealed 268 differentially expressed transcripts between them. There were 231 transcripts differentially expressed between C57BL/6 and two purported heat-resistant strains, AKR/N and MRL/MpJ-+/+. Experiment Overall Design: Total RNA of testes from 3 different strains of mice, C57BL/6, AKR/N and MRL/MpJ-+/+, were analyzed using microarray 430.20 chip. All mice were 8 weeks old, 2 mice/strain.
Project description:Bats as the only flying mammals incur a high metabolic cost during extended powered flight, which results in febrile-like temperatures without injury. Herein, we investigate the in vivo heat shock response (HSR) in the cave nectar bat Eonycteris spelaea. We demonstrate that E. spelaea exhibits enhanced physiological heat resistance, marked by reduced lethality, tissue damage and serum corticosterone levels in comparison to mice upon heat challenge. Additionally, E. spelaea did not exhibit an acute transcriptional response observed heat stress in mice. Instead, bats displayed a delayed and non-canonical HSR that did not involve the activation of classical heat shock related genes and pathways. This altered response in E. spelaea is attributed to the elevated basal expression of heat shock proteins, which we demonstrate to be a common characteristic exhibited by bats from diverse sub-orders, families and diets. Taken together, we demonstrate a distinct HSR in E. spelaea relative to the conventional model organism, mouse, which may provide insights to understand novel regulatory targets and effector proteins that underlie the mammalian heat shock response.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
Project description:We compared gene expression profiles between testes from C57BL/6 and C57BL/6-background congenic mouse strain B6.MRLc1-(D1Mit202M-bM-^@M-^SD1Mit403) carrying the telomeric region of MRL-type Chr 1 (67.97M-bM-^@M-^S81.63 cM) at 10 days after a single scrotal heat stress of 43M-BM-0C for 20 min. Heat-induced gene expression in mouse testis was measured at 10 days after a single heat exposure. The testes were isolated from 3 C57BL/6 and 3 B6.MRLc1-(D1Mit202M-bM-^@M-^SD1Mit403). C57BL/6 versus B6.MRLc1-(D1Mit202M-bM-^@M-^SD1Mit403) analysis was performed.
Project description:To study effect of VRK1 deletion on spermatogenesis of the mouse, transciptomic analysis of genes in postnatal 8-day testicular cells of wild type and VRK1-deficient Mus musculus was performed. Gene expression in testes from from wild type and VRK1-deficient mutant Mus musculus, respectively, was measured. Four independent experiments for wild type and mutant, respectively, were performed.