Comparative histomorphological and ultrastructural study of the luminal epithelium of the isthmus in laying and moulting domestic fowls (Gallus domesticus)

Immunohistochemical Changes in the Testicular Excurrent Duct System of Healthy, Male Japanese Quail (Coturnix coturnix japonica) Observed at 4, 6-7, 12, and 52 Weeks of Age

The immunolocalization of the cytoskeletal and the extracellular matrix proteins was investigated in the testicular excurrent duct system of healthy Japanese quail at 4, 6−7, 12 and 52 weeks of age. TdT dUTP Nick End Labeling (TUNEL) assay was used to assess apoptotic cell formation. The epithelia of the testicular excurrent duct system in birds of all age groups displayed various immunolabeling intensities and localization of cytokeratin 5 and beta-tubulin, while α-SMA was observed in epithelia only of 4-week-old birds. In all age groups, vimentin immunostaining was observed in the rete testes and efferent ductular epithelia, but not in the epididymal duct unit. The periductal smooth muscle cells of the excurrent duct system displayed variably intense immunopositivity with cytokeratin 5, desmin, fibronectin, α-SMA, and beta-tubulin. Furthermore, beta-tubulin and vimentin immunolabeled endothelial cells and fibroblasts with various intensities, while fibronectin immunostained extracellular matrices surrounding these cells. TUNEL-positive apoptotic cells were observed in the rete testes and efferent ductular epithelia, with increased frequency (p < 0.001) in 52-week-old birds. The study serves as a baseline normal for this region in healthy birds at 4, 6−7, 12, and 52 weeks of age, for comparison in future similar immunohistochemical studies involving environmental toxins affecting this region.

Transcriptomic Analysis of Laying Hens Revealed the Role of Aging-Related Genes during Forced Molting

Molting in birds provides us with an ideal genetic model for understanding aging and rejuvenation since birds present younger characteristics for reproduction and appearance after molting. Forced molting (FM) by fasting in chickens causes aging of their reproductive system and then promotes cell redevelopment by providing water and feed again. To reveal the genetic mechanism of rejuvenation, we detected blood hormone indexes and gene expression levels in the hypothalamus and ovary of hens from five different periods during FM. Three hormones were identified as participating in FM. Furthermore, the variation trends of gene expression levels in the hypothalamus and ovary at five different stages were found to be basically similar using transcriptome analysis. Among them, 45 genes were found to regulate cell aging during fasting stress and 12 genes were found to promote cell development during the recovery period in the hypothalamus. In addition, five hub genes (INO80D, HELZ, AGO4, ROCK2, and RFX7) were identified by WGCNA. FM can restart the reproductive function of aged hens by regulating expression levels of genes associated with aging and development. Our study not only enriches the theoretical basis of FM but also provides insights for the study of antiaging in humans and the conception mechanism in elderly women.

Autophagy in farm animals: current knowledge and future challenges

Autophagy (a process of cellular self-eating) is a conserved cellular degradative process that plays important roles in maintaining homeostasis and preventing nutritional, metabolic, and infection-mediated stresses. Surprisingly, little attention has been paid to the role of this cellular function in species of agronomical interest, and the details of how autophagy functions in the development of phenotypes of agricultural interest remain largely unexplored. Here, we first provide a brief description of the main mechanisms involved in autophagy, then review our current knowledge regarding autophagy in species of agronomical interest, with particular attention to physiological functions supporting livestock animal production, and finally assess the potential of translating the acquired knowledge to improve animal development, growth and health in the context of growing social, economic and environmental challenges for agriculture.Abbreviations: AKT: AKT serine/threonine kinase; AMPK: AMP-activated protein kinase; ASC: adipose-derived stem cells; ATG: autophagy-related; BECN1: beclin 1; BNIP3: BCL2 interacting protein 3; BVDV: bovine viral diarrhea virus; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; CMA: chaperone-mediated autophagy; CTSB: cathepsin B; CTSD: cathepsin D; DAP: Death-Associated Protein; ER: endoplasmic reticulum; GFP: green fluorescent protein; Gln: Glutamine; HSPA8/HSC70: heat shock protein family A (Hsp70) member 8; IF: immunofluorescence; IVP: in vitro produced; LAMP2A: lysosomal associated membrane protein 2A; LMS: lysosomal membrane stability; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MDBK: Madin-Darby bovine kidney; MSC: mesenchymal stem cells; MTOR: mechanistic target of rapamycin kinase; MTORC1: MTOR complex 1; NBR1: NBR1 autophagy cargo receptor; NDV: Newcastle disease virus; NECTIN4: nectin cell adhesion molecule 4; NOD1: nucleotide-binding oligomerization domain 1; OCD: osteochondritis dissecans; OEC: oviduct epithelial cells; OPTN: optineurin; PI3K: phosphoinositide-3-kinase; PPRV: peste des petits ruminants virus; RHDV: rabbit hemorrhagic disease virus; SQSTM1/p62: sequestosome 1; TEM: transmission electron microscopy.

The shell gland in laying and natural moulting commercial egg-type chickens: A histomorphological and ultrastructural study

The purpose of the present study was to determine the histological and ultrastructural changes in the luminal epithelium of the shell gland associated with natural moulting. Samples of the shell gland from laying (32 weeks old) and moulting (75 weeks old) hens were studied using histological, histochemical and electron microscopic techniques. In addition, TUNEL was used to demonstrate the distribution of apoptotic cells in the luminal epithelium of the shell gland. Autophagy, characterized by the presence of autophagosomes and autolysosomes, was evident in the early stages of degeneration in non-ciliated, ciliated and mitochondrial cells. The intermediate and advanced stages of regression in non-ciliated as well as mitochondrial cells occurred via apoptosis, while both apoptotic and necrotic ciliated cells were observed during the later stages of degeneration. The results of the present study suggest that a synergy of autophagy, apoptosis and necrosis is involved in the involution of the shell gland during natural moulting.