A-type lamin dynamics in bovine somatic cell nuclear transfer embryos

Area of Science:

• Reproductive Biology
• Developmental Biology
• Cell Biology

Background:

• Nuclear reprogramming is crucial for somatic cell nuclear transfer (SCNT) success.
• A-type nuclear lamin persistence has been suggested as an indicator of incomplete reprogramming in SCNT embryos.

Purpose of the Study:

• To investigate the distribution of A-type and B-type lamins in bovine SCNT embryos during early development.
• To determine if lamin A/C persistence serves as a reliable marker for incomplete nuclear reprogramming in SCNT.

Main Methods:

• Utilized monoclonal antibodies against A/C-type and B-type lamins.
• Compared lamin distribution in in vitro fertilization (IVF), parthenogenetic, and SCNT bovine embryos.
• Employed cycloheximide (CHX) to inhibit protein synthesis and assess lamin A/C origin and incorporation timing.

Main Results:

• Lamin A/C (A/C-346) was detected in early IVF embryos but not later stages; other antibodies stained all preimplantation embryos.
• Parthenogenetic and SCNT embryos exhibited similar lamin staining patterns to IVF embryos, suggesting proper nuclear reprogramming.
• Lamin A/C localization was not affected by protein synthesis inhibition, indicating maternal origin, but CHX activation delayed incorporation.

Conclusions:

• The distribution of lamin A/C in bovine SCNT embryos is comparable to IVF and parthenogenetic controls.
• Lamin A/C persistence is not a reliable marker for incomplete nuclear reprogramming in bovine SCNT embryos.
• SCNT embryos demonstrate successful nuclear architecture reprogramming during early development.