Protamine-1 represents a sperm specific gene transcript: a study in Callithrix jacchus and Bos taurus.

Area of Science:

• Reproductive Biology
• Epigenetics
• Developmental Biology

Background:

• Spermatozoa, though transcriptionally inactive, contain acetylated histones, suggesting a role in epigenetic inheritance.
• Acetylated histones are believed to be transmitted to the oocyte, influencing zygote gene expression and early embryogenesis.

Purpose of the Study:

• To investigate the presence of key transcripts in spermatozoa, oocytes, zygotes, and early embryos of the common marmoset (Callithrix jacchus) and cattle (Bos taurus).
• To evaluate the role of specific transcripts in fertilization and early embryonic development, including protamine-1 (PRM1), protamine-2 (PRM2), histones (H1, H3, H4), CREM, DNMT1, and TBP.

Main Methods:

• Reverse transcription polymerase chain reaction (RT-PCR) was employed.
• Analysis was conducted on spermatozoa, oocytes, zygotes, and two- and four-cell stage embryos from both marmoset and bovine models.

Main Results:

• Marmoset spermatozoa contained all tested transcripts; bull spermatozoa lacked PRM2.
• PRM1 transcripts were detected in marmoset and bovine spermatozoa, zygotes, and early embryos, suggesting paternal contribution.
• Specific histone and TBP transcripts were present across developmental stages in both species, with some variations.

Conclusions:

• PRM1 transcripts are likely delivered by spermatozoa to the oocyte in both marmoset and bovine species.
• These findings highlight the importance of paternal transcript contribution via sperm for successful fertilization and embryonic development.