Uterine structure and function contributes to the formation of the sandpaper-shelled eggs in laying hens

Whole transcriptome sequencing reveals key genes and ceRNA regulatory networks associated with pimpled eggs in hens

“…Eggs are considered one of the best sources of dietary protein and have always been an important part of the human diet ( Ahmed et al, 2021 ). Pimpled eggs are susceptible to breakage during transport due to their poor shell quality, and losses caused by pimpled eggs usually account for 1% of total egg production each year ( Khogali et al, 2021 ). Therefore, it is of great significance to conduct research on the formation mechanism of pimpled eggs.…”

“…Pimpled eggs are defective eggs, usually with excess calcified particles at the ends or equatorial areas ( Liu et al, 2017 ). In addition, pimpled eggs have weaker breaking strength than normal eggs, are more prone to breakage, and are also less favored by consumers ( Liu et al, 2017 ; Khogali et al, 2021 ). However the underlying mechanisms of pimpled egg production are not fully understood.…”

“…Egg shell formation takes about 20 h in the uterus and the required ions and matrix proteins come from uterine fluid secreted by the uterine tissues ( Marie et al, 2015 ; Ketta and Tumova, 2016 ). To date, only 1 study has analyzed the transcriptome of the uterus of hens laying pimpled eggs and found that some mRNAs, such as CALB1, SLC13A5 and POMC , may be associated with pimpled egg formation ( Khogali et al, 2021 ). Due to the lack of exploration into the regulatory roles of noncoding RNA ( ncRNA ) in uterine tissue of hens laying pimpled eggs, it is difficult to fully elucidate the molecular mechanisms underlying pimpled egg formation.…”

“…By sequencing the eggshell glands of ducks, Xu et al found that gga-miR-144-3p regulates the ABC transporter pathway by upregulating ABCG2 expression ( Xu et al, 2018 ). To date, research on the transcriptomics of hens producing pimpled eggs has solely focused on protein-coding genes, with no reported investigations into lncRNAs and miRNAs ( Khogali et al, 2021 ; Song et al, 2023 ). However, noncoding RNAs play a crucial role in elucidating the molecular regulatory mechanisms underlying pimpled egg formation.…”

Supplementing cholamine to diet lowers laying rate by promoting liver fat deposition and altering intestinal microflora in laying hens

“…Histomorphometric analysis of the intestine and uterus samples was performed as described previously ( Khogali et al, 2021 ).…”