Genomic Regions Related to White/Black Tail Feather Color in Dwarf Chickens Identified Using a Genome-Wide Association Study

Although the genetic foundation of chicken body feather color has been extensively explored, that of tail feather color remains poorly understood. In the present study, we used a synthetic chicken dwarf line (DW), derived from hybrids bred between a black tail chicken breed, Rhode Island Red (RIR), and a white tail breed, dwarf layer (DL), to investigate the genetic rules associated white/black tail color. Even though the body feathers are predominantly red, the DW line still comprises individuals with black or white tails after more than 10 generations of self-crossing and selection for the body feather color. We first performed four crosses using the DW chickens, including black-tailed males to females, reciprocal crosses between the black and white, and white males to females to elucidate the inheritance pattern of the white/black tail. We also performed a genome-wide association (GWA) analysis to determine the candidate genomic regions underlying the tail feather color using black tail chickens from the RIR and DW lines and white individuals from the DW line. In the crossing experiment, we found that (i) the white/black tail feather color is independent of body feather color; (ii) the phenotype is a simple autosomal trait; and (iii) the white is dominant to the black in the DW line. The GWA results showed that seven single-nucleotide polymorphisms (SNPs) on chromosome 24 were significantly correlated with tail feather color. The significant region (3.97–4.26 Mb) comprises nine known genes (NECTIN1, THY1, gga-mir-1466, USP2, C1QTNF5, RNF26, MCAM, CBL, and CCDC153) and five anonymous genes. This study revealed that the white/black tail feather trait is autosome-linked in DW chickens. Fourteen genes were found in the significant ~0.29 Mb genomic region, and some, especially MCAM, are suggested to play critical roles in the determination of white/black tail feather color. Our research is the first study on the genetics underlying tail feather color and could help further the understanding of feather pigmentation in chickens.

Genomic regions related to white/black tail feather color in Dwarf chickens detected using a genome-wide association study

Background: The genetic foundation of chicken tail feather color is not very well studied to date, though that of body feather color is extensively explored. In the present study, we used a synthetic chicken dwarf line (DW), which was originated from the hybrids between a black tail chicken breed, Rhode Island Red (RIR) and a white tail breed, Dwarf Layer (DL), to understand the genetic rules of the white/black tail color. The DW line still contain the individuals with black or white tails, even if the body feather are predominantly red, after more than ten generation of self-crossing and being selected for the body feather color. We firstly performed four crosses using the DW line chickens including black tail male to female, reciprocal crosses between the black and white, and white male to female to elucidate the inheritance pattern of the white/black tail. Furtherly, we performed a genome-wide association (GWA) analysis to determine the candidate genomic regions underlying the tail feather color by using black tail chickens from the RIR and DW chickens and white individuals from DW lines. Results: In the cross experiment, we found that (i) the white/black tail feather colors are independent of body feather color and (ii) the phenotype are autosomal simple trait and (iii) the white are dominant to the black in the DW lines. The GWA results showed that seven Single-nucleotide polymorphism (SNP) on chromosome 24 were significantly correlated with tail feather color. The significant region (3.97-4.26 Mb) perches nine known genes and five anonymous genes. The nine genes were: NECTIN1, THY1, gga-mir-1466, USP2, C1QTNF5, RNF26, MCAM, CBL and CCDC153. Conclusions: The study has revealed the white/black tail feather trait is autosome-linked in Dwarf chickens. In the genome significant ~0.29 Mb region, fourteen genes were found and some of them could play critical roles in the formation of white/black tail feather color, especially gene MCAM. Taken together, our research is the first study on genetics of tail feather color and could help the more understanding of feather pigmentation in chicken.

PHENOTYPIC CHARACTERISTICS AND BIOMETRICAL STUDY ON DIFFERENT BREEDS OF PIGEON IN NORTHERN BANGLADESH

The experiment was conducted to characterize different breeds of pigeon phenotypically and to study their body biometry, which are available in the northernBangladesh. During this study 30 farms were selected which have >20 pair of pigeons in the three study area namely Rajshahi, Natore and Pabna districts ofBangladesh. There about 15 breeds have been selected for the observation of phenotypic characteristics such as color of bill, eye, eyelid, skin, shank, toe, egg, head feather, neck feather, body feather, down feather, wing feather, tail feather and shape of bill, body and egg. The biometrical data were collected from the measurement of length of bill, head, body, shank, middle toe, wingspan and mature body weight. In this study the highest mean bill length was found 2.83±0.05cm in Strasser and lowest mean head length 5.00±0.00cm in Kormona, Nun and Jacobin. The highest mean body length was found 41.60±0.38cm in Strasser and lowest mean body length 30.00±0.43cm in Owl. The highest mean wingspan was found 81.00±0.51cm in Jacobin and lowest mean wingspan 60.45±0.76cm in kormona. The heighest mean shank length was found 3.40±0.13cm in Homer and lowest mean shank length 2.50±0.00cm in Giribug, Kormona, Nun, Satinette and Suachandan. The heighest mean middle toe length was found 4.40±0.05cm in pouter and lowest mean middle toe length 3.00±0.00cm in kormona. The heighest mean mature body weight was found 748.20±8.96gm in Strasser and lowest mean mature body weight 265.10±7.03gm in Giribug. Phenotypic correlation among bill length, head length, body length, wing span, shank length, middle toe length and mature body weight of these breeds of pigeon ranged from 0.233 to 0.789. The experiment’s result may contribute to breed up gradation, helps to formulate the conservation and improvement strategies for the breed as genetic resource.

A first evaluation on the use of Ardea albus feathers as bioindicators of mercury burden in Amazonian ecosystems

We evaluated in this study the total mercury concentration in feathers of Ardea albus collected in a colony located in the city of Belem-PA, Brazil in a prospective trial for its use as bioindicators of mercury burden in Amazonia ecosystems. An Atomic absorption spectrophotometry with gold amalgamation was used for the metal determination. The total mercury average concentration in body feathers was 2.2 ± 1.5 µg.g-1 and 1.3 ± 0.9 µg.g-1 in wing feathers. No correlation was observed between total mercury concentration and the length of body or wing feathers. Total mercury concentration was above 5 µg.g-1 dry weight in only one body feather sample.

Time-Activity Budgets of Harlequin Ducks Molting in the Gannet Islands, Labrador

We studied the time-activity budgets of Harlequin Ducks (Histrionicus histrionicus) molting at the Gannet Islands, Labrador in the summer of 1998. For the entire population, a large proportion of time was spent hauled out of the water (61.4%), and resting (53.5%). Only a small proportion of time was spent foraging (11.6%). Male Harlequin Ducks undergoing the pre-basic molt were hauled out of the water significantly more (92.2%) than males in basic plumage (8.1%). Males undergoing the pre-basic body feather molt foraged significantly less (1.7%) than males in basic plumage (17.7%). Harlequin Ducks do not appear to increase their food intake to meet the nutritional requirements of molt. Instead they may try to reduce thermoregulatory and maintenance costs by engaging in activities that do not consume much energy, and by staying out of cold water while their plumage is not intact. Furthermore, they may deliberately lose body mass while molting to regain the ability to fly at an earlier stage of wing molt.