Emc9, an ER membrane protein complex subunit, is crucial for the insertion of diverse transmembrane proteins into the plasma membrane. The endoplasmic reticulum (ER) membrane protein complex (EMC), composed of Emc1-7, Emc10, and either Emc8 or Emc9, is essential across cell types in this process [1].

In a study using Xenopus tropicalis as a research model, it was determined that EMC9 is important for neural crest development and the development of craniofacial structures. The phenotypes observed were similar to EMC1 loss-of-function, likely due to a similar mechanism of dysfunction in transmembrane protein topogenesis [1]. Also, in cattle, EMC9 was identified as a candidate gene potentially controlled by significant eQTLs related to endometrial receptivity in recipient cows, which may be relevant for improving in-vitro production of dairy cattle embryos [2].

In conclusion, Emc9 is vital for the insertion of transmembrane proteins. Model-based research, such as in Xenopus tropicalis, has revealed its significance in neural crest and craniofacial development. In cattle, its potential role in endometrial receptivity shows its importance in reproductive-related biological processes. Understanding Emc9's functions can provide insights into congenital malformations in humans and reproductive traits in cattle.