Genetic differentiation and phylogenetic relationships among 15 Atherina boyeri populations from several marine and lagoon or lake sites in Greece were investigated using mtDNA analysis. PCR-RFLP analysis of 12s, 16s rRNA genes and D-loop revealed 23 haplotypes. All the lake or lagoon populations, as well as the Kymi and Kalymnos populations that originated from sites with lagoonlike environmental conditions, showed haplotypes 1-6, clearly distinguishable from the marine populations, which exhibited types 7-23. The genetic divergence values estimated between the lagoon and the marine populations ranged from 5.55 to 10.45%. The high genetic differentiation observed between these two types of populations is also highlighted by the dendrograms obtained using UPGMA and maximum parsimony methods.

The colonization of Madagascar by Austronesian-speaking people during AD 50–500 represents the most westerly point of the greatest diaspora in prehistory. A range of economically important plants and animals may have accompanied the Austronesians. Domestic chickens (Gallus gallus) are found in Madagascar, but it is unclear how they arrived there. Did they accompany the initial Austronesian-speaking populations that reached Madagascar via the Indian Ocean or were they late arrivals with Arabian and African sea-farers? To address this question, we investigated the mitochondrial DNA control region diversity of modern chickens sampled from around the Indian Ocean rim (Southeast Asia, South Asia, the Arabian Peninsula, East Africa and Madagascar). In contrast to the linguistic and human genetic evidence indicating dual African and Southeast Asian ancestry of the Malagasy people, we find that chickens in Madagascar only share a common ancestor with East Africa, which together are genetically closer to South Asian chickens than to those in Southeast Asia. This suggests that the earliest expansion of Austronesian-speaking people across the Indian Ocean did not successfully introduce chickens to Madagascar. Our results further demonstrate the complexity of the translocation history of introduced domesticates in Madagascar.

Chickens ( Gallus gallus domesticus ) from the Americas have long been recognized as descendants of European chickens, transported by early Europeans since the fifteenth century. However, in recent years, a possible pre-Columbian introduction of chickens to South America by Polynesian seafarers has also been suggested. Here, we characterize the mitochondrial control region genetic diversity of modern chicken populations from South America and compare this to a worldwide dataset in order to investigate the potential maternal genetic origin of modern-day chicken populations in South America. The genetic analysis of newly generated chicken mitochondrial control region sequences from South America showed that the majority of chickens from the continent belong to mitochondrial haplogroup E. The rest belongs to haplogroups A, B and C, albeit at very low levels. Haplogroup D, a ubiquitous mitochondrial lineage in Island Southeast Asia and on Pacific Islands is not observed in continental South America. Modern-day mainland South American chickens are, therefore, closely allied with European and Asian chickens. Furthermore, we find high levels of genetic contributions from South Asian chickens to those in Europe and South America. Our findings demonstrate that modern-day genetic diversity of mainland South American chickens appear to have clear European and Asian contributions, and less so from Island Southeast Asia and the Pacific Islands. Furthermore, there is also some indication that South Asia has more genetic contribution to European chickens than any other Asian chicken populations.

BackgroundNorfolk Island has a population of feral chickens which could be the result of domestic stock introduced onto the island by British settlers in 1788. However, there is ongoing debate about their origins because multiple human arrivals to the island may have brought chickens with them. Here we investigate the genetic origins of these feral chickens by sequencing their mitochondrial control region. We infer their phylogenetic relationships using a large dataset of novel sequences from Australian mainland domestic chickens and published sequences from around the world.ResultsEleven control region haplotypes were found among the Norfolk Island feral and Australian mainland domestic chickens. Six of the Norfolk Island haplotypes fall within haplogroup E, but given the worldwide distribution of this haplogroup, the putative European origin of these chickens requires further investigation. One haplotype common among Norfolk Island and Australian samples belonged to a subgroup of haplogroup D, which appears to be restricted to chickens from Indonesia, Vanuatu and Guam.ConclusionsOur data show that at least two mitochondrial DNA haplogroups (D and E) have contributed to the genetic make-up of Norfolk Island feral chickens. In addition, we have provided insights into the discrete geographical distribution and diversity of the chicken haplogroup D. In view of the worldwide interest in the characterisation of poultry resources, further assessment of chicken populations of Island Southeast Asia and the Pacific region is warranted.

The genetic differentiation of 11 Greek Atherina hepsetus populations have been investigated at the mtDNA level. Restriction fragment length polymorphism analysis of three mtDNA regions (12S rRNA, 16S rRNA and D-loop) amplified by PCR was used. Eighteen restriction endonucleases were found to have at least one recognition site at the three mtDNA regions studied. Fifteen different composite haplotypes were detected among the populations studied while 80.6% of the individuals were grouped in two common haplotypes. The estimated net nucleotide sequence divergence values between the populations ranged from 0.003 to 0.379%, while the Nst value of 0.092 indicates the existence of low interpopulation genetic differentiation. The findings clearly support the existence of a single panmictic population in the sampling area.