Influence of freezing at different temperatures on the transcription activity of buffalo sperm chromatin

The effect of freezing at different temperatures, -20 degrees C, -70 degrees C and -196 degrees C, on the transcription activity of buffalo sperm chromatin was investigated. The kinetic data of incorporation of 3H-UTP in pre-mRNA indicate that temperatures of -70 degrees C and -196 degrees C are the most favourable for preservation, since transcription activity gradually increases with time, reaching maximum values within 30 min. Freezing at -20 degrees C or preservation at 4 degrees C leads to a rapid decrease of transcriptional activity within 10 and 20 min, respectively. It is suggested that the optimal temperature for storage of buffalo spermatozoa is below -20 degrees C as judged by the transcription assay.