A single, mild, transient scrotal heat stress causes DNA damage, subfertility and impairs formation of blastocysts in mice
| Autor: | Catriona Paul, Alison A. Murray, Norah Spears, Philippa T. K. Saunders |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Male
Embryology DNA damage Cleavage Stage Ovum Placenta medicine.medical_treatment Embryonic Development Fertilization in Vitro Biology Heat Stress Disorders Morula Andrology Mice Endocrinology Pregnancy Testis Scrotum In Situ Nick-End Labeling medicine Animals Blastocyst Spermatogenesis Infertility Male In vitro fertilisation Embryogenesis Obstetrics and Gynecology Embryo Organ Size Cell Biology Spermatozoa Sperm Chromatin Mice Inbred C57BL medicine.anatomical_structure Reproductive Medicine Immunology Female Germ cell DNA Damage |
| Zdroj: | REPRODUCTION. 136:73-84 |
| ISSN: | 1741-7899 1470-1626 |
| Popis: | Infertility represents a major clinical problem and 50% of cases are attributable to the male partner. Testicular function is temperature dependent, and in both man and mouse the position of the testes in the scrotum ensures that they are kept at between 2 and 8 degrees C below core body temperature. We used a mouse model to investigate the impact of a single, transient, mild, scrotal heat stress (38, 40 or 42 degrees C for 30 min) on testicular function, sperm DNA integrity and embryo survival. We detected temperature-dependent changes in testicular architecture, number of apoptotic cells and a significant reduction in testis weight 7 and 14 days after heat stress at 42 degrees C. We report for the first time that DNA strand breaks (gamma-H2AX-positive foci) were present in spermatocytes recovered from testes subjected to 40 or 42 degrees C. Fertility of heat-stressed males was tested 23-28 d after treatment (sperm at this time would have been spermatocytes at time of heating). Paternal heat stress at 42 degrees C resulted in reduced pregnancy rate, placental weight and litter size; pregnancies from the 40 degrees C group had increased resorptions at e14.5. Abnormalities in embryonic development were detected at e3.5 and in vitro fertilisation with sperm recovered 16 h or 23 d after scrotal stress at 42 degrees C revealed a block in development between the 4-cell and blastocyst stages. This study has provided evidence of temperature-dependent effects on germ cell DNA integrity and highlighted the importance of an intact paternal genome for normal embryo development. |
| Databáze: | OpenAIRE |
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