Progress 07/01/21 to 06/30/22
Outputs
Target Audience:Scientific community, poultry breeders, students Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Training opportunities were provided for 8 undergrad and 2 grad students. Student participated in a wide range of activities, including but not restricted to feeding breeders (hens and roosters), collecting eggs, setting eggs in an incubator, candling eggs to identify viable embryos, hatching eggs, raising chicks, tagging chicks (wing-band), recording live weight, routine checking on live chickens, postmortem tissue sample and data collection, tissue sample processing (homogenization) and RNA isolation from tissue samples. RNA quality and quantity checks, blood sample collection and separating plasma from blood cells. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals? Histopathologic Analysis of 567 p. major muscle samples harvested at necropsy Spatial transcriptomic analysis using Visium Spatial Transcriptomic method RNA and DNA isolation from blood and tissue samples RNAi assays for candidate genes to knock-down gene expression in satellite cells in co-PI's lab
Impacts
What was accomplished under these goals?
Live animal experiment: A new experiment was conducted using commercial broiler chickensat the University of Delaware. Cobb Breeders including 30 hens (Cobb500) and 6 roosters (Cobb Vantage)were obtained from abreeders farm in New Holland, PA.Breeders were randomly placed in 2 breeder houses, 15 hens and 3 roosters per house. Egg were collected twice daily and stored in a cold room until incubation.Eggs from one week of egg collection were incubated in an egg incubator at 100 °F, 70% humidity, and checked by candling at embryonic day 11;non-viableeggs were disposed properly.Upon hatching,chickenswere placed in chicken houses at the University of Delawareand raised in accordance with the Animal Care and Use Handbook 2019 of the UD College of Agriculture and Natural Resources. Chicks had free access to feed and water throughout the experiment.Tissue samples were harvested post-euthanasia at day 14 15, 16, 17 post-hatch immediately frozen in liquid nitrogen, and stored in a −80 °C freezer until subsequent analysis.Sex was determined post-euthanasia during necropsy by visual inspection of gonads and will subsequently be confirmed by PCR-based sexing, as we described before (Zhuo et al., 2017). During necropsy, the entire p. major muscle was removed, weighed, and samples from the p. major muscle were taken from the cranial aspect (which is typically the fastest growing part of the muscle) of the left p. major muscle. Two sets of samples, one for histopathologic analysis and another for gene expression analysis were collected from the same sampling location.While this project is focused on the p. major muscle, two important metabolic tissues (liver and adipose) were also collected forpotentialfuture studies.Body weight were recorded and cardiac blood samples were collectedpost-euthanasia. In total, tissue and blood samples were collected from 534 chicks over 5 hatches. Histopathologic Analysis: One set of p. majorsamples harvested at necropsy were placed in 10% neutral buffered formalin for histologic analysis. Tissues were trimmed, embedded transversely and longitudinally in paraffin, sectioned to 4 μm thickness, and autostained with Hematoxylin and Eosin. Slides will be analyzed microscopically in a blinded manner by students trained by the project collaborator Dr. Brannick-board certified veterinary anatomic pathologist screening for lesions of vasculitis/phlebitis, abnormal lipid deposition, and WB (myofiber damage, myositis, regeneration, fibrosis, edema, etc.).
Publications
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