A Bird's-Eye View of Endangered Species Conservation: Avian Genomics and Stem Cell Approaches for Green Peafowl (Pavo muticus)

Abstract

Aves ranks among the top two classes for the highest number of endangered and extinct species in the kingdom Animalia. Notably, the IUCN Red List classified the green peafowl as endangered. This highlights promising strategies using genetics and reproductive technologies for avian wildlife conservation. These platforms provide the capacity to predict population trends and enable the practical breeding of such species. The conservation of endangered avian species is facilitated through the application of genomic data storage and analysis. Storing the sequence is a form of biobanking. An analysis of sequence can identify genetically distinct individuals for breeding. Here, we reviewed avian genomics and stem cell approaches which not only offer hope for saving endangered species, such as the green peafowl but also for other birds threatened with extinction.

Keywords: avian conservation; avian genomics; avian stem cells; green peafowl; peafowl.

Figure 1

Phenotypic differences between green peacock (a), and green peahen (b) in comparison with hybrid peafowl (P. muticus × P. cristatus) (c) and plumage color variations (d). A mature male peacock displays a striking appearance after reaching the third year of age. They possess a small head with a turquoise blue color, slightly green, adorned with a compact crown of long blue–green feathers with a green tufted crest. The face is white with a blue stripe stretching from the base of the beak to the eye, while the area of the ear patch and lower jaw features a yellow crescent stripe are shown in the inset. The neck exhibits long and iridescent metallic-green feathers, and the breast and saddle are green with a metallic sheen. The primary feathers are light brown, while the secondary feathers appear bluish-grey. The shoulders and base of the wing have a grey–brown color with a light-blue–green sheen. The tarsus of the leg is in a greyish-black shade with spur found in both sexes. The primary color of the tertiary feather is yellow–green. Note that female peahen resembles a male with reduced iridescent plumage, a smaller neck, breast, and back scaly features, and a short train without ocelli and herl. (Source: courtesy of Santisak Thanomsing).

Figure 1

Phenotypic differences between green peacock (a), and green peahen (b) in comparison with hybrid peafowl (P. muticus × P. cristatus) (c) and plumage color variations (d). A mature male peacock displays a striking appearance after reaching the third year of age. They possess a small head with a turquoise blue color, slightly green, adorned with a compact crown of long blue–green feathers with a green tufted crest. The face is white with a blue stripe stretching from the base of the beak to the eye, while the area of the ear patch and lower jaw features a yellow crescent stripe are shown in the inset. The neck exhibits long and iridescent metallic-green feathers, and the breast and saddle are green with a metallic sheen. The primary feathers are light brown, while the secondary feathers appear bluish-grey. The shoulders and base of the wing have a grey–brown color with a light-blue–green sheen. The tarsus of the leg is in a greyish-black shade with spur found in both sexes. The primary color of the tertiary feather is yellow–green. Note that female peahen resembles a male with reduced iridescent plumage, a smaller neck, breast, and back scaly features, and a short train without ocelli and herl. (Source: courtesy of Santisak Thanomsing).

Figure 2

Strategy for preserving green peafowl using stem cell technology. Tissue from the calamus area of a green peafowl feather can be collected for primary culture to obtain feather fibroblasts, which can then be used for cellular reprogramming without genome modification to generate induced pluripotent stem cells (iPSCs). Alternatively, blastodermal cells from a stage equivalent to the chicken embryo EGK X stage can serve as a source to obtain embryonic stem cells (ESCs). Fertile eggs can also be further incubated to reach a stage equivalent to the chicken HH stage 14 for the isolation of circulating primordial germ cells (cPGCs), or a stage equivalent to chicken HH stage 33–35 for the isolation of gonadal PGCs (gPGCs) and embryonic skin tissue for embryonic fibroblast derivation. These embryonic fibroblasts can also be used for cellular reprogramming to generate green peafowl iPSCs. Both iPSCs and ESCs can potentially serve as the sources for generating an entirely new animal body. In this case, it can be achieved through transplantation into a sterile recipient egg, where the original blastodermal cells have already been irradiated and removed. Green peafowl PGCs can also be transplanted onto recipient eggs to create chimeric males and females, which can later cross to produce offspring, some of which may potentially be purebred green peafowl. The collection of different types of genetic resources, such as iPSCs, ESCs, PGCs, and fibroblasts, can be stored in a biobank for long-term preservation.