Chicken Genetic Resources Research Articles

Genotype by Environment interactions for egg number and egg weight of five dual-purpose chicken breeds in different zones of Oromia region in Ethiopia

The African Chicken Genetic Gain (ACGG) project (https://africacgg.net/) aims at backyard poultry optimization by commercial dual-purpose breeds introduction into Africa. To measure benefits, genotype by environment interaction (GxE) analysis provides guidance while predicting environmental effects on production traits of breeds. A survey among Ethiopian poultry smallholders showed egg sale being the most important purpose of keeping village chickens in Oromia. Data was available about laying of 894 ACGG chickens in Oromia. Hence current research questions were: 1) Does GxE take place? 2) Which breed performs best regarding laying and in which environment within Oromia? Traits investigated were egg number and egg weight of five breeds (S-RIR, Sasso, Horro, Kuroiler and Koekoek) located in three zones (East Hararge, East and West Shoa) and 5 districts (Adami Tulu, Bako Tibe, Dano, Dugda and Haromaya) in Oromia. Observations were taken as group measure performing weighted analyses. GxE was only present for egg number with magnitude strongest for zone. S-RIR performed best for both traits in both environments, except Kuroiler performing better in East Shoa for egg number and Koekoek for egg weight. This indicates success of crossbreed S-RIR. Sasso and Horro performed worst supported by previous research for Horro but not Sasso. Low precipitation in East Shoa caused bigger distance in egg number predictions, being higher for S-RIR and lower for Horro and Sasso compared to West Shoa. Apart from these final conclusions, social context of breeding and data collection difficulties should not be forgotten. Just like relevance of other performance trait analyses.

Identification of genes involved in inbreeding depression of reproduction in Langshan chickens.

ObjectiveInbreeding depression of reproduction is a major concern in the conservation of native chicken genetic resources. Here, based on the successful development of strongly inbred (Sinb) and weakly inbred (Winb) Langshan chickens, we aimed to evaluate inbreeding effects on reproductive traits and identify candidate genes involved in inbreeding depression of reproduction in Langshan chickens.MethodsA two-sample t-test was performed to estimate the differences in phenotypic values of reproductive traits between Sinb and Winb chicken groups. Three healthy chickens with reproductive trait values around the group mean values were selected from each of the groups. Differences in ovarian and hypothalamus transcriptomes between the two groups of chickens were analyzed by RNA sequencing (RNA-Seq).ResultsThe Sinb chicken group showed an obvious inbreeding depression in reproduction, especially for traits of age at the first egg and egg number at 300 days (p<0.01). Furthermore, 68 and 618 differentially expressed genes (DEGs) were obtained in the hypothalamus and ovary between the two chicken groups, respectively. In the hypothalamus, DEGs were mainly enriched in the pathways related to vitamin metabolism, signal transduction and development of the reproductive system, such as the riboflavin metabolism, Wnt signaling pathway, extracellular matrix-receptor interaction and focal adhesion pathways, including stimulated by retinoic acid 6, serpin family F member 1, secreted frizzled related protein 2, Wnt family member 6, and frizzled class receptor 4 genes. In the ovary, DEGs were significantly enriched in pathways associated with basic metabolism, including amino acid metabolism, oxidative phosphorylation, and glycosaminoglycan degradation. A series of key DEGs involved in folate biosynthesis (gamma-glutamyl hydrolase, guanosine triphosphate cyclohydrolase 1), oocyte meiosis and ovarian function (cytoplasmic polyadenylation element binding protein 1, structural maintenance of chromosomes 1B, and speedy/RINGO cell cycle regulator family member A), spermatogenesis and male fertility (prostaglandin D2 synthase 21 kDa), Mov10 RISC complex RNA helicase like 1, and deuterosome assembly protein 1) were identified, and these may play important roles in inbreeding depression in reproduction.ConclusionThe results improve our understanding of the regulatory mechanisms underlying inbreeding depression in chicken reproduction and provide a theoretical basis for the conservation of species resources.

Genome-wide analysis of the role of DNA methylation in inbreeding depression of reproduction in Langshan chicken

Inbreeding depression of chicken reproduction is a major concern in the conservation of chicken genetic resources. To investigate the potential DNA methylation sites involved in the inbreeding depression of chicken reproduction, we carried out whole-genome bisulfite sequencing (WGBS) of hypothalamus and ovary tissues from the strongly and weakly inbred Langshan chickens, respectively. 5948 and 4593 differentially methylated regions (DMRs) were identified in the hypothalamus and ovary between the strongly and weakly inbred Langshan chickens, respectively. Large numbers of DMR-related genes (DMGs) were enriched in reproduction-related pathways. By combining the WGBS and transcriptome data, two DMRs in SRD5A1 and CDC27 genes were inferred as the most likely biomarkers of inbreeding depression of reproduction in Langshan chicken. Our study provides the first systematic investigation of the DNA methylation changes in strongly inbred chickens, and extends our understanding of the regulatory mechanisms underlying inbreeding depression in chicken reproduction.

Phylogeny and conservation priority assessment of Asian domestic chicken genetic resources

Chicken genetic resources are gradually decreasing in genetic diversity; thus, a theoretical basis for conservation is needed. The genetic diversity and phylogeography of domestic chickens from 10 countries in Asia and red jungle fowl were investigated by analyzing the mitochondrial DNA D-loop hypervariable segment (HVS). The order of domestic chickens distributed in 31 management units in Asia in terms of conservation priority was assessed based on genetic diversity and genetic contribution rate models. A total of 219 haplotypes were distributed in seven clades, with variants identified at 103 sites. Phylogenetic analysis revealed seven maternal origins of Asian domestic chickens. Multiple subspecies of red jungle fowl were involved in the domestication of chickens in the three centers of origin: the Indian subcontinent (clade D), China (clades B, C, E and F) and Southeast Asia (clade A). The domestication center of the G clade remains unknown. The order in terms of conservation priority based on genetic diversity was as follows: northwestern and northeastern Yunnan, China; Sri Lanka; Guangxi, China; Japan; etc. The order in terms of conservation priority based on the genetic contribution rate was as follows: northwestern Yunnan, China; Sri Lanka; Japan; Papua New Guinea; etc. This study provided new insights for the conservation and evaluation of native genetic resources.

The Role of Molecular Tools in Genetic Diversity Conservation of Indigenous Chicken Production, Tanzania: Short Communication

Molecular techniques refers to methods used in molecular biology, biochemistry, genetics and biophysics which involve manipulation and analysis of DNA and RNA. Molecular techniques can also be used in biology to study genetic diversity and variation. Genetic diversity refers to the total number of genetic characteristics in the genetic makeup of a species. It shows similarity and variation that exist between breeds of the same species. Genetic diversity serves as a way for populations to adapt to changing environment. An increase loss of genetic diversity has been observed in most of agricultural species and particularly chicken genetic resources are considered to be the most threatened. Selective breeding by humans have led to the creation of many breeds characterized by high productivity, leading to the displacement of local breeds and posing a threat to the survival of many native breeds. Genetic resources are the building blocks for chicken development. The relevance of genetic diversity conservation in chicken production cannot be overemphasized because genes play a great role in formation of breeds and species. With recent advances in molecular technology, a number of techniques for in-depth genome analysis and evaluation of genetic variation in different breeds of chicken have been developed.

English

This study aimed at characterizing phenotypes, production systems and the reproductive performance of indigenous chickens in Rwanda. Indigenous chickens (n=529) from 265 chicken rearing households drawn from all the five provinces of Rwanda were used in this study and analysis was performed using Statistical Analysis Systems (SAS, version 9.2) software. Four comb types were observed, with strawberry (51%) being most dominant, as was whiteness of ear lobes (57%). Rounded ear lobe shape (92%) and curved beaks (99.6%) were both almost universal. Beak colour varied between green, black, yellow and brown with the latter most prevalent (51%). Evenly distributed feathers were most common (99.8%) whereas naked-neck phenotype was rare (0.2%). Almost all chickens had brown eyes, and thick skins (88.4%) that were yellow-coloured (69%). Most chickens (39%) had yellow coloured shanks. Significant variations were observed in age at sexual maturity for both male and female chickens across provinces (p>0.05). The biggest egg clutches were from the western province (14.7 eggs) while the smallest was 6.6 eggs in the southern. Egg hatchability was highest (85%) in the western province and lowest (52%) in the eastern province.We conclude that the Rwanda indigenous chickens might have useful genetic potential, and planning for proper and sustainable utilization of this indigenous chicken genetic resource is the best way forward. Key words: Indigenous chickens, phenotypes, production, reproduction, population structure.

Chicken germplasms and their conservation in Bangladesh: A review

The present article addresses the scenario of chicken genetic resources, their production and reproduction performances and their conservation in Bangladesh. The chickens, among other poultry species available in the country, are the most versatile component for meat and egg production. The chicken germplasms available in the country are indigenous, exotic, crossbred, and commercial hybrid. The indigenous chicken population is comprised of Non-descript Desi (ND), Naked Neck (NN), Aseel (AS), Hilly (H), Native Dwarf and Jungle Fowl etc. The exotic chicken such as, White Leghorn (WL), White Rock (WR), White Cornish (WC), Rhode Island Red (RIR), Australorp, Fayoumi, Barred Plymouth Rock (BPR) etc. are imported mostly to upgrade the indigenous stock. The crossbred of different chickens are used in the country in intensive, semi-intensive and scavenging management system. The commercial hybrid such as grandparent stock (GP), parent stock (PS), commercial broiler, commercial layer etc. has got most popularity for meat and egg production in the country. Conservation and improvement program of endangered native chicken such as Aseel and Native Dwarf chicken should be taken both in-situ or ex-situ in vivo by public sector/research institutes/universities.&#x0D; SAARC J. Agri., 17(1): 119-134 (2019)

Whole-genome SNP data unravel population structure and signatures of selection for black plumage of indigenous chicken breeds from Jiangxi province, China.

Ten indigenous chicken breeds were originally distributed in Jiangxi Province, China, and they define a critical component of Chinese chicken genetic resources. We have investigated the population genetics of seven Jiangxi chicken breeds using 600K chicken BeadChip SNP data. To provide a genome-wide perspective for the population structure of all 10 Jiangxi chicken breeds, we herein genotyped 78additional individuals from the seven breeds and 63 chickens from three uninvestigated breeds-Yugan Black (YG), Nancheng Black (NC) and Wanzai Yellow using 55K chicken SNP arrays. We then explored merged data of 17101 SNPs from 235 individuals to infer the population structure of the 10 breeds. We showed that NC and YG are two regional populations of the same breed, as individuals from the two populations clustered together to form a branch separate from the other breeds in the neighbor-joining tree, they always grouped together in multidimensional principal component analyses and they displayed an identical pattern of ancestral lineage composition. Hence, NC and YG should be considered a single breed in the state-supported conservation scheme. Moreover, we conducted a genome scan for signatures of selection for black plumage. bayescan and hapflk analyses of two contrasting groups (three black-feathered breeds vs. six non-black-feathered breeds) consistently detected 25 putative regions under selection. Nine pigmentation- associated genes (DCT, SLC24A5, SLC30A4, MYO5A, CYP19A1, NADK2, SLC45A2, GNAQ and DCP2) reside within these regions, and these genes are interesting candidates for black plumage and provide a starting point for further identification of causative mutations for black feathers in chicken.

Phenotypic Characterization and Distribution of Sensi-1 Agrinak Chicken

The utilization of local chicken genetic resources in Indonesia is increasing after the government program to achieve food sovereignty including livestock products. In the year of 2017, the Indonesian Research Institute for Animal Production (IRIAP) released SenSi-1 Agrinak chicken breed to be used as commercial meat type of local chicken in Indonesia. This paper describes development and distribution of the SenSi-1 Agrinak. This breed was selected from the native breed of Sentul chicken, originated from Ciamis District of West Java Province. The Sentul male was selected to achieve average live weight of 1 kg/bird at 10 weeks of age, with grey (G) and black spotted white (BSW) plumage color and pea-comb type. After six generations of selection, SenSi-1 Agrinak was released as an improved local meat-type chicken breed. License to private local chicken breeders is expected to increase SenSi-1 Agrinak population and distribution. Collaboration with several Assessment Institutes for Agricultural Technology (AIAT) and implementation of #BEKERJA-Ministry of Agriculture program can accelerate population and distribution of SenSi-1 Agrinak chicken to farmers throughout Indonesia.

Effectiveness of DMSO concentration on recovery rate and viability of primordial germ cell of Gaok chicken

&lt;p class="abstrak2"&gt;Recent technological developments to produce germ line chimeras with primordial germ cell (PGC) transfer into the recipient embryo provide an opportunity to conserve and retrieval of chicken genetic resources in complete form. The study was conducted to obtain the most effective DMSO percentage to recovery rate and viability of Gaok chicken PGC after freezing which will later be feasible to be transferred. In this study, the eggs of Gaok chicken were incubated for about 2.5 - 3 days to obtain embryos at stages 14 - 16. Blood retrieval was done through the dorsal aorta using micropipettes under microscope. The procedure of PGC isolation of Gaok chicken with centrifugation gradient was using nycodenz as a substance. Commercially available cryoprotectants (dimethyl sulfoxide = DMSO) were used for PGC freezing. Isolated and frozen PGCs of Gaok chicken were diluted with cryoprotectants containing 2.5; 5 and 10% DMSO in fetal bovine serum (FBS). The recovery rate of 2.5; 5 and 10% DMSO concentration were 36.4; 48.2 and 48 % respectively. The viability of PGC after freezing was significantly higher for 5% DMSO compared with 2.5% DMSO (P&amp;lt;0.05), but not different from 10% DMSO. It can be concluded that the concentration DMSO of 5 % was effectve contration in freezing Gaok chicken PGC.&lt;/p&gt;

Hazra chicken: A precious germplasm in need of immediate scientific intervention

Indian poultry diversity is still largely unexplored, even though more than half of the germplasm is endangered. The present study was planned to ascertain the genetic diversity of local poultry population of Odisha (Hazra) using 25 Simple Sequence Repeat markers. All the loci were retained for diversity analysis due to their behavior as neutral markers in this population. Hazra chicken population was found to host a very high level of diversity. This conclusion is based on the large number of alleles observed across loci (average14.96, range 6-21), and by the high expected heterozygosity (average 0.80, range 0.50-0.92). In spite of high within-breed variation, signatures of inbreeding were detected by the FIS index, which was positive (0.218±0.03) in the population. Hazra chicken population presented the highest heterozygote deficiency as compared to all the 17 recognized poultry breeds of India. Nonsignificant heterozygote excess on the basis of infinite allele model (IAM) along with a normal 'L'-shaped distribution of mode-shift analysis test, indicated an absence of bottleneck. In summary, molecular data conclude that Hazra population possesses a very interesting pool of chicken genetic resources due to their high genetic diversity. Increased level of inbreeding is indicating that flock management and reproduction strategies deserve attention.

Breeding for the improvement of indigenous chickens of Bangladesh: evaluation of performance of first generation of indigenous chicken

Pure breeding is necessary for the conservation and improvement of indigenous chicken genetic resources. Present research is a part of the long-term selection program being undertaken to evaluate the performance and expected response to selection of first generation (G1) of three indigenous chicken genotypes under intensive management in Bangladesh. A total of 1439-day-old chicks comprising of 3 genotypes namely Naked Neck (NN), Hilly (H) and Non-descript Desi (ND) were hatched for this study. In first generation (G1), selection was practiced on body weight at 8 and 16 weeks of age, on the basis of their breeding value. At 40-week of age, selection will be practiced on the basis of an index comprising the parameters of age at first egg (ASM), body weight (BW), egg production (EP) and egg weight (EW). At 8, 10 and 12 weeks of age, six birds from each genotype were slaughtered to analyze the meat yield traits. Data were analyzed in CRD by General Linear Model Univariate Procedure. Significantly (P&lt;0.001) highest body weight of day-old chicks (28.65±0.12 g) and daily weight gain in all stages were found in H genotype than other two genotypes. Although there was significant (P&lt;0.001) difference in live weight between ages at slaughter, dressing percent (65.87 - 66.89 %) of different ages was similar (P&gt;0.05) but was affected (P&lt;0.001) by genotype. Body weight at 8 weeks of age was expected to improve by 58.98 vs. 11.50; 81.56 vs. 40.91 and 53.81 vs. 15.82 g; respectively for ND, H and NN males and females. In terms of body weight and growth traits H genotype was superior and NN genotype was for dressing percentage. As a result of selection; chick weight, body weight at all stages increased and ASM reduced in first generation than foundation stock. These findings give an impetus for continuing the pure breeding research for more generations.Asian J. Med. Biol. Res. March 2017, 3(1): 72-79

Breeding for the improvement of indigenous chickens of Bangladesh: performance of foundation stock

Selection is one of the vital tools for improving the indigenous chicken genetic resources. A total of 1585-day-old chicks comprising of 3 types of chicken namely Naked Neck (NN), Hilly (H) and Non-descript Deshi (ND) were hatched for this study to form foundation stock. Improvement target of egg weight was to increase by 1g and improvement target of egg production rate was to increase by 2 % per generation. In foundation stock, selection was practiced at 40-week of age, on the basis of an index comprising the parameters of age at first egg (ASM), body weight(BW), egg production(EP) and egg weight(EW). Data were analyzed in CRD by General Linear Model (GLM) Univariate Procedure. Significantly highest fertility (82.71%) and hatchability (82.20%) were found in ND genotype. Significantly (P&lt;0.001) highest body weight of day-old chicks and daily weight gain was found in H genotype than other two genotypes. There was a non-significant (P&gt;0.05) variation in FCR among the native chicken genotypes. NN genotype (3.46%) had non-significantly (?2 = 3.62; P &gt; 0.05) higher chick mortality than ND (1.63%) and H (2.11%) at brooding period (0-4 weeks). Significantly (P&lt;0.01) higher dressing percentage was found in NN (64.58) genotype than ND (60.26) and H (61.70) genotypes. Non-significantly higher egg production in selected group was found in H (70) genotype than ND (68) and NN (67) genotypes. Significantly (P&lt;0.001) highest shape index and Haugh unit were found in H and ND genotypes, respectively. As a result of selection, egg production is expected to improve by 0.562, 0.932 and 0.755%, respectively for ND, H and NN genotypes. In terms of reproductive traits ND was superior, in terms of productive traits H genotype was superior and in terms of dressing percentage and breaking strength NN genotype was superior. These findings of the study also give an impetus for continuing the research for more generations to fulfill the objectives of the long-term programme.Asian J. Med. Biol. Res. March 2017, 3(1): 80-87

A comparison of genetic variations among native andsome local chicken populations in Turkey

Genetic variations among native and local chicken populations in six different locations across Turkey were established using 15 ISSR primers, and produced 87 bright and reproducible bands. According to pairwise genetic differentiation among the populations (GST), the highest genetic differentiation was determined between the Samsun and Yozgat population and the lowest was observed between the Dulkadirli and Budak populations. Shannon’s index was calculated to be 0.239. The gene flow (Nm) among the populations was estimated to be 3.489, which indicated low levels of differentiation among the populations. Analysis of Molecular Variance (AMOVA) identified 13% of the total genetic variation between the populations and the rest of the differences were 87% within the populations. Cluster analysis revealed two main branches, one leading to the domestic chicken population collected from Samsun in the Black Sea region of Turkey, the other branch clustered into two branches; one branch consisting of the Denizli Native Chicken population and the other one of domestic chicken populations sampled from Central Anatolia populations. The study is important to clarify the indigenous chicken genetic resources in Turkey. The results could be used for future breeding research conducted by either the public or private sectors.

Phenotypic characterization of the indigenous chickens &amp;lt;i&amp;gt;(Gallus gallus)&amp;lt;/i&amp;gt; in the northwest of Algeria

Abstract. This study was conducted to characterize local chickens in the northwest of Algeria based on some phenotypic traits and to look at prediction of body weight from morphometric measurements (linear body). The results indicated that the predominant comb colour was dark red (77.8 %), followed by light red (22.2 %). Tarsus colour was either white (40.9 %), grey (31 %), yellow (15.39 %), dark (8.05 %), or green (4.51 %). Most chickens (81.7 %) had orange eyes, while 10.37 and 7.92 % had yellow and dark-brown eyes, respectively. The dominant earlobe colour was white (73.96 %), followed by red (16.81 %). The remaining proportion included yellow and red-mottled yellow and black earlobes. Proportions of the adaptive genes were low. Incidences of Na, F, Pti, Cr, R, and P genes were 8.82, 0.45, 1.22, 5.54, 3.35, and 4.7 %, respectively. The calculated gene frequencies ranged from 0.002 to 0.045. Variations were also found in quantitative morphological traits. Sex-associated differences (P &lt; 0.001) were observed in almost all the parameters evaluated with higher values recorded for males. Phenotypic correlations of body weight and biometric traits ranged from −0.13 to 0.88 and −0.15 to 0.97 for males and females, respectively. From the factor analysis with varimax rotation of the intercorrelated traits, three principal components which accounted for 71.6 and 73.2 % of the total variance were extracted in males and females, respectively. Orthogonal body shape characters derived from the factor analysis accounted for 84.3 and 94.2 % of the variation in body weight of males and females, respectively. Information obtained from this study could be useful in an appropriate management, breeding programmes for selection and utilization of Algerian chicken genetic resources.

Identification of quantitative trait loci for body temperature, body weight, breast yield, and digestibility in an advanced intercross line of chickens under heat stress

BackgroundLosses in poultry production due to heat stress have considerable negative economic consequences. Previous studies in poultry have elucidated a genetic influence on response to heat. Using a unique chicken genetic resource, we identified genomic regions associated with body temperature (BT), body weight (BW), breast yield, and digestibility measured during heat stress. Identifying genes associated with a favorable response during high ambient temperature can facilitate genetic selection of heat-resilient chickens.MethodsGenerations F18 and F19 of a broiler (heat-susceptible) × Fayoumi (heat-resistant) advanced intercross line (AIL) were used to fine-map quantitative trait loci (QTL). Six hundred and thirty-one birds were exposed to daily heat cycles from 22 to 28 days of age, and phenotypes were measured before heat treatment, on the 1st day and after 1 week of heat treatment. BT was measured at these three phases and BW at pre-heat treatment and after 1 week of heat treatment. Breast muscle yield was calculated as the percentage of BW at day 28. Ileal feed digestibility was assayed from digesta collected from the ileum at day 28. Four hundred and sixty-eight AIL were genotyped using the 600 K Affymetrix chicken SNP (single nucleotide polymorphism) array. Trait heritabilities were estimated using an animal model. A genome-wide association study (GWAS) for these traits and changes in BT and BW was conducted using Bayesian analyses. Candidate genes were identified within 200-kb regions around SNPs with significant association signals.ResultsHeritabilities were low to moderate (0.03 to 0.35). We identified QTL for BT on Gallus gallus chromosome (GGA)14, 15, 26, and 27; BW on GGA1 to 8, 10, 14, and 21; dry matter digestibility on GGA19, 20 and 21; and QTL of very large effect for breast muscle yield on GGA1, 15, and 22 with a single 1-Mb window on GGA1 explaining more than 15 % of the genetic variation.ConclusionsThis is the first study to estimate heritabilities and perform GWAS using this AIL for traits measured during heat stress. Significant QTL as well as low to moderate heritabilities were found for each trait, and these QTL may facilitate selection for improved animal performance in hot climatic conditions.

Genetic diversity and relationship of Indonesian indigenous chickens inferred from microsatellite DNA markers

A total of 1178 individuals of nearly complete sampling of 49 populations belong to 14 most popular Indonesian indigenous chicken breeds, geographically localized in different islands, were genotyped using 20 microsatellite DNA markers to investigate their molecular diversity and genetic relationship. In total, 259 alleles were observed among 49 populations of Indonesian indigenous chickens across 20 loci. The mean number of alleles (MNA) per locus ranged from 4.20 to 7.60. The observed (HO) and expected heterozygosity (HE) values averaged over loci varied from 0.50 to 0.67 and from 0.55 to 0.72, respectively, and they displayed a similar distribution pattern to that observed for MNA across the populations. The results indicated that there was rich and unique genetic diversity among most of the populations. The presence of significantly positive FIS values (P < 0.05), suggested the occurrence of inbreeding within most of these populations, leading to partition genetic diversity among the major islands. Some localized chicken populations have developed a distinct genetic background due to historical trading and long term geographic isolation. On the other hand, a few populations kept in urban areas may have been genetically introgressed with commercial chicken breeds/lines to some extent, forming different genetic structure. These findings will serve as scientific basis for the development of rational policies to sustainably conserve and utilize these unique Indonesian indigenous chicken genetic resources.

FGF, Insulin, and SMAD Signaling Cooperate for Avian Primordial Germ Cell Self-Renewal

SummaryPrecise self-renewal of the germ cell lineage is fundamental to fertility and reproductive success. The early precursors for the germ lineage, primordial germ cells (PGCs), survive and proliferate in several embryonic locations during their migration to the embryonic gonad. By elucidating the active signaling pathways in migratory PGCs in vivo, we were able to create culture conditions that recapitulate this embryonic germ cell environment. In defined medium conditions without feeder cells, the growth factors FGF2, insulin, and Activin A, signaling through their cognate-signaling pathways, were sufficient for self-renewal of germline-competent PGCs. Forced expression of constitutively active MEK1, AKT, and SMAD3 proteins could replace their respective upstream growth factors. Unexpectedly, we found that BMP4 could replace Activin A in non-clonal growth conditions. These defined medium conditions identify the key molecular pathways required for PGC self-renewal and will facilitate efforts in biobanking of chicken genetic resources and genome editing.

Frequencies of Some Morphological Features in Indigenous Chickens of South- Western Nigeria

Morphological features of chicken genetic resources must be carefully identified and considered in developing breeding strategies. The study was carried out to determine the frequencies of morphological features in indigenous chickens of South-Western Nigeria, using Lagos, Ogun, Osun and Oyo States as case study. Five major chicken markets (Mushin in Lagos State, Itoku and Ipokia in Ogun State, Olu-ode in Osun State and Molete in Oyo State) were used as study locations and three thousand, three hundred and thirteen chickens were observed in the five locations. Ipokia had the highest number (1,549) of chickens and Molete had the least (307) number of chickens. The traits observed included: feather structure, feather distribution, feather morphology, plumage colour, ear lobe colour, skin colour and shank colour. The data collected were subjected to descriptive statistics and inferential statistical analysis was also done for the results using chi-square test. It was observed that for those traits that recorded significant variation, there had been selection for these traits due to the high market value attached to them by attaching preference to some of its variants which were observed. Knowledge and well documentation of the potentials of indigenous chickens can help provide crucial information for a comprehensive breeding policy and full utilization of the animal.

Native Chicken Production in Indonesia: A Review

Indonesia is a country rich in native chicken genetic resources. There are 31 native chicken breed in Indonesia. Native chicken farming was developed for decades. In early period of 1907's, mostly farmers reared their native chicken by traditional system (about 80%). In 1980s until now, the number of native chicken farmers which rear native chicken by semi intensive and intensive system have been increasing. These rearing system changing have significantly increased the native chicken productivity. The major constraints for the development of native chicken i.e. low growth rate, risks of high mortality, low egg production. Many research results stated that improving in breeding, feeding and management aspect will increase native chicken production. The information and data contained in this paper is the result of study literature for scientific papers, either in the form of journals, books, or proceedings, and livestock statistics books. This paper is made to support the development of native chickens in Indonesia.