Paternal Lineages Research Articles

Paternal genetic history of the Yong population in northern Thailand revealed by Y-chromosomal haplotypes and haplogroups

We have determined the distribution of Y-chromosomal haplotypes and haplogroups in the Yong population, one of the largest and well-known ethnic groups that began migrating southward from China to Thailand centuries ago. Their unique mass migration pattern provided great opportunities for researchers to study the genetic links of the transboundary migration movements among the peoples of China, Myanmar and Thailand. We analysed relevant male-specific markers, such as Y-STRs and Y-SNPs, and the distribution of 23 Y-STRs of 111 Yong individuals and 116 nearby ethnic groups including the Shan, Northern Thai, Lawa, Lua, Skaw, Pwo and Padong groups. We found that the general haplogroup distribution values were similar among different populations; however, the haplogroups O1b-M268 and O2-M112 constituted the vast majority of these values. In contrast with previous maternal lineage studies, the paternal lineage of the Yong did not relate to the Xishuangbanna Dai people, who represent their historically documented ancestors. However, they did display a close genetic affinity to other prehistoric Tai-Kadai speaking groups in China such as the Zhuang and Bouyei. Low degrees of genetic admixture within the populations who belonged to the Austroasiatic and Sino-Tibetan linguistic families were observed in the gene pool of the Yong populations. Resettlement in northern Thailand in the early part of the nineteenth century AD, by way of mass migration trend, was able to preserve the Yong's ancestral genetic background in terms of the way they had previously lived in China and Myanmar. Our study has revealed similar genetic structures among ethnic populations in northern Thailand and southern China, and has identified and emphasized an ancient Tai-Kadai patrilineal ancestry line in the Yong ethnic group.

Paternal morphine self-administration produces object recognition memory deficits in female, but not male offspring.

Parental drug use around or before conception can have adverse consequences for offspring. Historically, this research has focused on the effects of maternal substance use on future generations but less is known about the influence of the paternal lineage. This study focused on the impact of chronic paternal morphine exposure prior to conception on behavioral outcomes in male and female progeny. This study sought to investigate the impact of paternal morphine self-administration on anxiety-like behavior, the stress response, and memory in male and female offspring. Adult, drug-naïve male and female progeny of morphine-treated sires and controls were evaluated for anxiety-like behavior using defensive probe burying and novelty-induced hypophagia paradigms. Hypothalamic-pituitary-adrenal (HPA) axis function was assessed by measuring plasma corticosterone levels following a restraint stressor in male and female progeny. Memory was probed using a battery of tests including object location memory, novel object recognition, and contextual fear conditioning. Paternal morphine exposure did not alter anxiety-like behavior or stress-induced HPA axis activation in male or female offspring. Morphine-sired male and female offspring showed intact hippocampus-dependent memory: they performed normally on the long-term fear conditioning and object location memory tests. In contrast, paternal morphine exposure selectively disrupted novel object recognition in female, but not male, progeny. Our findings demonstrate that paternal morphine taking produces sex-specific and selective impairments in object recognition memory while leaving hippocampal function largely intact.

Genetic analysis of male Hungarian Conquerors: European and Asian paternal lineages of the conquering Hungarian tribes

According to historical sources, ancient Hungarians were made up of seven allied tribes and the fragmented tribes that split off from the Khazars, and they arrived from the Eastern European steppes to conquer the Carpathian Basin at the end of the ninth century AD. Differentiating between the tribes is not possible based on archaeology or history, because the Hungarian Conqueror artifacts show uniformity in attire, weaponry, and warcraft. We used Y-STR and SNP analyses on male Hungarian Conqueror remains to determine the genetic source, composition of tribes, and kin of ancient Hungarians. The 19 male individuals paternally belong to 16 independent haplotypes and 7 haplogroups (C2, G2a, I2, J1, N3a, R1a, and R1b). The presence of the N3a haplogroup is interesting because it rarely appears among modern Hungarians (unlike in other Finno-Ugric-speaking peoples) but was found in 37.5% of the Hungarian Conquerors. This suggests that a part of the ancient Hungarians was of Ugric descent and that a significant portion spoke Hungarian. We compared our results with public databases and discovered that the Hungarian Conquerors originated from three distant territories of the Eurasian steppes, where different ethnicities joined them: Lake Baikal-Altai Mountains (Huns/Turkic peoples), Western Siberia-Southern Urals (Finno-Ugric peoples), and the Black Sea-Northern Caucasus (Caucasian and Eastern European peoples). As such, the ancient Hungarians conquered their homeland as an alliance of tribes, and they were the genetic relatives of Asiatic Huns, Finno-Ugric peoples, Caucasian peoples, and Slavs from the Eastern European steppes.

Test of the hybrid origin of <i>Broussonetia</i> × <i>kazinoki</i> (Moraceae) in Korea using molecular markers

Broussonetia × kazinoki Siebold has long been utilized as a major component in the manufacturing of Korean traditional paper, hanji, and has been suggested as a hybrid species of B. papyrifera and B. monoica. By applying three molecular markers, chloroplast (cp) ndhF-rpl32 IGS, a nuclear ribosomal internal transcribed spacer, and the TOPO6 gene, the hybrid origin of B. × kazinoki is tested. As a result, B. × kazinoki in Korea is demonstrated to be a hybrid of B. monoica × B. papyrifera, most likely formed naturally in Korea. The cp haplotypes detected provided information about the origins and genetic diversity of the maternal lineage B. monoica and paternal lineage B. papyrifera. The two nuclear markers were supplemented to each other, leading to the discovery of introgression in Broussonetia.

Downregulation, Blood Type, Paternal Lineage, and Genetic Variants in Ovarian Cancer: A Call for Tumor Suppressor Genes Effectiveness

This article calls for a deeper look at the role of downregulation, blood type, paternal lineage, and genetic variants in ovarian cancer. While considering the importance of oncogenes, associated tumors, expression, or overexpression, signal transducers, and downregulation, it suggests that a viable platform for tumor suppressor genes effectiveness is needed for early detection. The role of DNA methylation to gene silencing, proteins, RNA alteration in the development of metastatic tissues in late stage of ovarian cancer, which require further elucidation and research, continue to suggest that methylation, and tumor suppressor genes from BRCA1 and BRCA2 mutations are exceptionally critical, and warrant further monitoring of genetic predispositions. The role of controlled induction of ARHI associated with the X chromosome, or loss of ARHI expression and faulty breast genes is another quest for added oncological inquiries. Additionally, arguments relating to ABO blood group and its association to epithelial ovarian cancer, throughout the literature postulate that ABO genes on chromosomes 9q34 are of high consideration. Reviewing blood type correlation with ovarian cancer, through a paternal lineage connection suggesting strong inheritance patterns in first degree relatives, suggests there is an X-linked variation, and X-chromosome variation in the process. A better understanding of cancer screening by means of genetic testing, as an early detection tool, and downregulation are worthy research lenses in the fight of ovarian cancer.

Prenatal Glucocorticoid Exposure Results in Changes in Gene Transcription and DNA Methylation in the Female Juvenile Guinea Pig Hippocampus Across Three Generations

Synthetic glucocorticoids (sGC) are administered to women at risk for pre-term delivery, to mature the fetal lung and decrease neonatal morbidity. sGC also profoundly affect the fetal brain. The hippocampus expresses high levels of glucocorticoid (GR) and mineralocorticoid receptor (MR), and its development is affected by elevated fetal glucocorticoid levels. Antenatal sGC results in neuroendocrine and behavioral changes that persist in three generations of female guinea pig offspring of the paternal lineage. We hypothesized that antenatal sGC results in transgenerational changes in gene expression that correlate with changes in DNA methylation. We used RNASeq and capture probe bisulfite sequencing to investigate the transcriptomic and epigenomic effects of antenatal sGC exposure in the hippocampus of three generations of juvenile female offspring from the paternal lineage. Antenatal sGC exposure (F0 pregnancy) resulted in generation-specific changes in hippocampal gene transcription and DNA methylation. Significant changes in individual CpG methylation occurred in RNApol II binding regions of small non-coding RNA (snRNA) genes, which implicates alternative splicing as a mechanism involved in transgenerational transmission of the effects of antenatal sGC. This study provides novel perspectives on the mechanisms involved in transgenerational transmission and highlights the importance of human studies to determine the longer-term effects of antenatal sGC on hippocampal-related function.

Y-chromosome haplogroups from Hun, Avar and conquering Hungarian period nomadic people of the Carpathian Basin

Hun, Avar and conquering Hungarian nomadic groups arrived to the Carpathian Basin from the Eurasian Steppes and significantly influenced its political and ethnical landscape, however their origin remains largely unknown. In order to shed light on the genetic affinity of above groups we have determined Y chromosomal haplogroups and autosomal loci, suitable to predict biogeographic ancestry, from 49 individuals, supposed to represent the power/military elit. Haplogroups from the Hun-age are consistent with Xiongnu ancestry of European Huns. Most of the Avar-age individuals carry east Eurasian Y haplogroups typical for modern north-eastern Siberian and Buryat populations and their autosomal loci indicate mostly un-admixed Asian characteristics. In contrast the conquering Hungarians seem to be a recently assembled population incorporating un-admixed European, Asian as well as admixed components. Their heterogeneous paternal and maternal lineages indicate similar supposed phylogeographic origin of males and females, derived from Central-Inner Asian and European Pontic Steppe sources.

Paternal lineages and forensic parameters based on 23 Y-STRs (Powerplex® Y23) in Mestizo males from Mexico City.

We analyzed 307 Mexican-Mestizo (admixed) males from Mexico City with the Powerplex® Y23 system. The complete list of Y-STR haplotypes was uploaded into the YHRD database (accession number YA004275). The discriminatory capacity (98.70 %) and gene diversity (D = 99.99 %) were calculated, improving the haplotype diversity regarding previous studies in Mexico based on 17 Y-STRs and 12 Y-STRs. Haplogroup distribution assignment was inferred by means of two different online-available algorithms. The Native American Q* haplogroup was the most frequent (66.2 %), followed by the European R1b lineage (19.5 %). In addition, eight Eurasian (3.9%) and two African (6.6%) haplogroups were observed in this population sample from Mexico City. Interestingly, AMOVA test showed a low but significant differentiation among Mexican-Mestizos (Fst = 1.52%; p = 0.0000), suggesting that four population clusters allow to explain their genetic structure according to geographic criteria: north, west, center, and south.

Population genetic analysis of 36 Y-chromosomal STRs yields comprehensive insights into the forensic features and phylogenetic relationship of Chinese Tai-Kadai-speaking Bouyei.

Male-specifically inherited Y-STRs, harboring the features of haploidy and lack of crossing over, have gained considerable attention in population genetics and forensic investigations. Goldeneye® Y-PLUS kit was a recently developed amplification system focused on the genetic diversity of 36 Y-chromosomal short tandem repeats (Y-STRs) in East Asians. However, no population data and corresponding forensic features were reported in China. Here, 36 Y-STRs were first genotyped in 400 unrelated healthy Tai-Kadai-speaking Bouyei male individuals. A total of 371 alleles and 396 haplotypes could be detected, and the allelic frequencies ranged from 0.0025 to 0.9875. The haplotype diversity, random match probability and discrimination capacity values were 0.9999, 0.0026 and 0.9900, respectively. The gene diversity (GD) of 36 Y-STR loci in the studied group ranged from 0.0248 (DYS645) to 0.9601 (DYS385a/b). Population comparisons between the Guizhou Bouyei and 80 reference groups were performed via the AMOVA, MDS, and phylogenetic relationship reconstruction. The results showed that the population stratification was almost consistent with the geographic distribution and language-family, both among Chinese and worldwide ethnic groups. Our newly genotyped Bouyei samples show a close affinity with other Tai-Kadai-speaking groups in China and Southeast Asia. Our data may provide useful information for paternal lineage in the forensic application and population genetics, as well as evidence for archaeological and historical research.

A genomic inference of the White Plymouth Rock genealogy

ABSTRACTCrossing of populations has been, and still is, a central component in domestication and breed and variety formation. It is a way for breeders to utilize heterosis and to introduce new genetic variation into existing plant and livestock populations. During the mid-19th century, several chicken breeds that had been introduced to America from Europe and Asia became the founders for those formed in the USA. Historical records about the genealogy of these populations are often unclear and inconsistent. Here, we used genomics in an attempt to describe the ancestry of the White Plymouth Rock (WPR) chicken. In total, 150 chickens from the WPR and 8 other stocks that historical records suggested contributed to its formation were whole-genome re-sequenced. The admixture analyses of the autosomal and sex chromosomes showed that the WPR was likely founded as a cross between a paternal lineage that was primarily Dominique, and a maternal lineage where Black Java and Cochin contributed in essentially equal proportions. These results were consistent and provided quantification with the historical records that they were the main contributors to the WPR. The genomic analyses also revealed genome-wide contributions (<10% each) by Brahma, Langshan, and Black Minorca. When viewed on an individual chromosomal basis, contributions varied considerably among stocks.

Analysis of paternal lineages legacy in Salta province, northwestern argentina

Seventeen Y-STRs included in the AmpFlSTR® Yfiler® PCR Amplification Kit were studied for 174 individuals from Salta province (northwest of Argentina). A total of 166 different haplotypes were identified. The Haplotype Diversity (HD) was 0.9992 and the Discrimination capacity (DC) was 95.4%. The high efficiency in forensic parameters demonstrates that this set of markers provides a powerful tool in forensic casework in Salta population. Haplogroup composition reflects the Amerindian and European legacy of this population together with a minor African contribution.

Applying machine learning algorithms to a real forensic case to predict Y-SNP haplogroup based on Y-STR haplotype

Y-chromosome single nucleotide polymorphisms (Y-SNPs) have lower mutation rate compared with Y-chromosome short tandem repeats (Y-STRs), thus more informative in paternal lineage identification. Here we present a case about the personal identification of an unidentified cadaver using machine learning methods to determine Y-SNP haplogroup by Y-STR haplotype. Two possible haplotypes from two different male lineages were found after searching national Y-STR databases. Six methods, k-Nearest Neighbor, Naive Bayesian Model, Logistic Regression, Support Vector Machine, Decision Tree, and Random Forest were used to predict the haplogroup based on Y-STR haplotype. These two haplotypes are predicted into two different haplogroups, O2a2b1a2a1 and O2a2b1a2a1a3. The predicted results were further verified by Y-SNP genotyping. It indicates that the mismatch of the two haplotypes may not originate from mutation, but due to different lineages. In this case, machine learning algorithms, especially Support Vector Machine and Random Forest show the potential of discriminating different lineages.

Inferring the genetic structure of Northwestern Argentina by uniparental SNP typing

The genetic background of South American populations is the result of four major genetic admixture events. To investigate the maternal and paternal lineages, we analyzed mitochondrial DNA (mt-DNA): A2, B2, C, D1; and Y-chromosome (Y-DNA) haplogroups (hg): R1b1b2, Q1a3a, G2a, I, J2, E1b1b, based on SNP typing by real time PCR and high-resolution melting analysis. Individuals from Northwestern Argentina (NWA) (n = 187) were studied and compared with Buenos Aires Metropolitan Area’s inhabitants (BUE) (n = 107) and recently arrived immigrants from Bolivia (BOL) (n = 100), Paraguay (PAR) (n = 54) and Peru (PER) (n = 52). Native American (NA) mt-DNA hgs were the most frequent in all regions (89,8%–98,1%), except for BUE (43%), being B2 the most prevalent (42,6%–58% versus 8,4% in BUE). Regarding Y-DNA hg, a greater contribution of the non-Native American (non-NA) lineage was found in all populations (61,5%–99%), except for BOL (32,7%). Moreover, the most frequent hg observed were R1b1b2 (50% PAR, 46,6% BUE, 30,2% NWA) and Q1a3a (67,3% BOL, 38,5% PER). A high percentage of NA mt-DNA/non-NA Y-DNA was represented (53,8%–63,5%), excepting BUE (41,7%) and BOL (26,9%). Data obtained is consistent with historical information underscoring the complex genetic ancestry of melting pot countries. The results offer additional tools for forensic investigation; molecular epidemiological and anthropological studies.

Evaluation of 13 rapidly mutating Y-STRs on a Dravidian pedigree

The effectiveness of a rapidly mutating Y-STRs multiplex assay (RM Y-STRs) containing 13 RM Y-STR markers was compared with the AmpFℓSTR™ Yfiler™ PCR Amplification Kit (Yfiler) with conventional Y-STR markers for their efficiency in differentiating males within the same paternal lineage. Samples from 4 generations comprising 16 Dravidian males (15 father-son pairs) were analysed with both assays. Mutations were observed in 3 father-son pairs in the RM Y-STRs profiles while only 2 mutations were observed in the Y-filer profiles. Even though not many mutations were observed as anticipated, this study still emphasised the importance of RM Y-STRs when differentiation between males within the same paternal lineage is required and also indicated the need for mutation rates for different populations.

\u0391 de novo 3.8-Mb inversion affecting the EDA and XIST genes in a heterozygous female calf with generalized hypohidrotic ectodermal dysplasia

BackgroundIn mammals, hypohidrotic ectodermal dysplasia (HED) is a genetic disorder that is characterized by sparse hair, tooth abnormalities, and defects in cutaneous glands. Only four genes, EDA, EDAR, EDARADD and WNT10A account for more than 90% of HED cases, and EDA, on chromosome X, is involved in 50% of the cases. In this study, we explored an isolated case of a female Holstein calf with symptoms similar to HED.ResultsClinical examination confirmed the diagnosis. The affected female showed homogeneous hypotrichosis and oligodontia as previously observed in bovine EDAR homozygous and EDA hemizygous mutants. Under light microscopy, the hair follicles were thinner and located higher in the dermis of the frontal skin in the affected animal than in the control. Moreover, the affected animal showed a five-fold increase in the number of hair follicles and a four-fold decrease in the diameter of the pilary canals. Pedigree analysis revealed that the coefficient of inbreeding of the affected calf (4.58%) was not higher than the average population inbreeding coefficient (4.59%). This animal had ten ancestors in its paternal and maternal lineages. By estimating the number of affected cases that would be expected if any of these common ancestors carried a recessive mutation, we concluded that, if they existed, other cases of HED should have been reported in France, which is not the case. Therefore, we assumed that the causal mutation was dominant and de novo. By analyzing whole-genome sequencing data, we identified a large chromosomal inversion with breakpoints located in the first introns of the EDA and XIST genes. Genotyping by PCR-electrophoresis the case and its parents allowed us to demonstrate the de novo origin of this inversion. Finally, using various sources of information we present a body of evidence that supports the hypothesis that this mutation is responsible for a skewed inactivation of X, and that only the normal X can be inactivated.ConclusionsIn this article, we report a unique case of X-linked HED affected Holstein female calf with an assumed full inactivation of the normal X-chromosome, thus leading to a severe phenotype similar to that of hemizygous males.

Maternal folic acid supplementation does not counteract the deleterious impact of prenatal exposure to environmental pollutants on lipid homeostasis in male rat descendants.

Prenatal exposure to persistent organic pollutants (POPs) has been associated with the development of metabolic syndrome-related diseases in offspring. According to epidemiological studies, father's transmission of environmental effects in addition to mother's can influence offspring health. Moreover, maternal prenatal dietary folic acid (FA) may beneficially impact offspring health. The objective is to investigate whether prenatal FA supplementation can overcome the deleterious effects of prenatal exposure to POPs on lipid homeostasis and inflammation in three generations of male rat descendants through the paternal lineage. Female Sprague-Dawley rats (F0) were exposed to a POPs mixture (or corn oil) +/- FA supplementation for 9 weeks before and during gestation. F1 and F2 males were mated with untreated females. Plasma and hepatic lipids were measured in F1, F2, and F3 males after 12-h fast. Gene expression of inflammatory cytokines was determined by qPCR in epididymal adipose tissue. In F1 males, prenatal POPs exposure increased plasma lipids at 14 weeks old and hepatic lipids at 28 weeks old and prenatal FA supplementation decreased plasma total cholesterol at 14 weeks old. Prenatal POPs exposure decreased plasma triglycerides at 14 weeks old in F2 males. No change was observed in inflammatory markers. Our results show an impact of the paternal lineage on lipid homeostasis in rats up to the F2 male generation. FA supplementation of the F0 diet, regardless of POPs exposure, lowered plasma cholesterol in F1 males but failed to attenuate the deleterious effects of prenatal POPs exposure on plasma and hepatic lipids in F1 males.

Endocrine-disrupting chemicals alter the neuromolecular phenotype in F2 generation adult male rats

Endocrine-disrupting chemical (EDC) exposures to the fetus have long-lasting effects on health and disease in adulthood. Such EDC exposure to the F1 fetuses also reaches the germ cells that become the F2 generation. Previously, we demonstrated that adult social and communicative behaviors such as ultrasonic vocalizations and mating behaviors were altered by EDCs in F2 rats, especially males. In the current study, we used the brains of these F2 males to ascertain the underlying molecular changes in the hypothalamus related to these behavioral outcomes. Their progenitors were Sprague-Dawley rat dams, treated on pregnancy days 8 to 18 with one of three treatments: a polychlorinated biphenyl (PCB) mixture, Aroclor 1221, selected because it is weakly estrogenic; the anti-androgenic fungicide vinclozolin (VIN); or the vehicle, 6% dimethylsulfoxide in sesame oil (VEH). In adulthood, F1 male and female offspring were bred with untreated partners to generate paternal or maternal lineages of the F2 offspring, the subjects of molecular work. Quantitative real-time PCR was conducted in the medial preoptic area (POA) and the ventromedial nucleus (VMN) of the hypothalamus, selected for their roles in social and sexual behaviors. Of the genes assessed, steroid hormone receptors (estrogen receptor α, androgen receptor, progesterone receptor) but not dopamine receptors 1 and 2 or DNA methyltransferase 3a expression were altered, particularly in the VIN males. Several significant correlations between behavior and gene expression were also detected. These results suggest that preconceptional exposure of male rats to EDCs at the germ cell stage alters the neuromolecular phenotype in adulthood in a lineage-dependent manner.

Germ Granules Govern Small RNA Inheritance.

SummaryIn C. elegans nematodes, components of liquid-like germ granules were shown to be required for transgenerational small RNA inheritance. Surprisingly, we show here that mutants with defective germ granules can nevertheless inherit potent small RNA-based silencing responses, but some of the mutants lose this ability after many generations of homozygosity. Animals mutated in pptr-1, which is required for stabilization of P granules in the early embryo, display extraordinarily strong heritable RNAi responses, lasting for tens of generations. Intriguingly, the RNAi capacity of descendants derived from mutants defective in the core germ granule proteins MEG-3 and MEG-4 is determined by the genotype of the ancestors and changes transgenerationally. Further, whether the meg-3/4 mutant alleles were present in the paternal or maternal lineages leads to different transgenerational consequences. Small RNA inheritance, rather than maternal contribution of the germ granules themselves, mediates the transgenerational defects in RNAi of meg-3/4 mutants and their progeny. Accordingly, germ granule defects lead to heritable genome-wide mis-expression of endogenous small RNAs. Upon disruption of germ granules, hrde-1 mutants can inherit RNAi, although HRDE-1 was previously thought to be absolutely required for RNAi inheritance. We propose that germ granules sort and shape the RNA pool, and that small RNA inheritance maintains this activity for multiple generations.

Multi-scale archaeogenetic study of two French Iron Age communities: From internal social- to broad-scale population dynamics

Ancient DNA (aDNA) research can address anthropological questions at both the broad continental scale to provide elements of discussion regarding ancient human population dynamics and the very small spatial scale to document population social functioning. In the present study, we propose an original approach combining local- and broad-scale issues, applied to two contemporaneous groups dated from the Late Iron Age period and originating from Northern France. Our analyses targeted uniparental markers (mitochondrial DNA (mtDNA) and the Y chromosome) and permitted the characterization of 43 maternal and 17 paternal lineages for the Urville-Nacqueville necropolis (UN) as well as 27 maternal and 19 paternal lineages for the Gurgy ‘Les Noisats’ (GLN) tumulus. Data in hand provided a unique opportunity to document Gallic communities' genetic diversities and discuss their internal social dynamics as well as their genetic affinities with other ancient European groups. At the local scale, our study first highlighted patrilocal residence rules and patrilinearity for these Gallic groups, in concordance with textual sources and archaeological data. Second, the gene pool characterization indicated that the UN necropolis welcomed a more cosmopolitan community than did the GLN tumulus and that the funerary space organization in the UN was correlated to the genetic structuration of the community. These local scale characteristics were put into perspective for broad-scale discussions and highlighted different genetic affinities of the UN and GLN communities with ancient European groups. Both communities appeared inserted in distinct exchange networks that may have been responsible for the slight differentiation of their maternal gene pools. Finally, we demonstrated that the sub-groups encountered in the UN necropolis (maternally differentiated) presented very distinct genetic affinities with ancient or contemporaneous human groups from other Western European regions. Consequently, our study reinforces the idea that the identification of genetically differentiated groups within archaeological sites and discussion concerning their specific composition constitute a clear prerequisite before addressing broad-scale phylogeographical issues.

WA-CMS-based iso-cytoplasmic restorers derived from commercial rice hybrids reveal distinct population structure and genetic divergence towards restorer diversification

One hundred diverse iso-cytoplasmic restorer (ICR) lines carrying WA cytoplasm indicated significant but moderate variability for agro-morphological traits as well as for the microsatellite-based allele patterns. There were two major groups of ICRs based on agro-morphological clustering. Simple sequence repeat (SSR) markers identified allelic variants with an average of 2.48 alleles per locus and the gene diversity (GD) ranged from 0.02 to 0.62 at different loci. ICR lines showed a genetic structure involving two sub-populations, POP1 and POP2. Both the subpopulations had the presence of admixture lines. Nearest ancestry-based grouping of ICRs by neighbour-joining (NJ) method showed near similar grouping as that of sub-population division. The POP2 was the largest group but with fewer admixed lines. POP1 was more distinct than POP2. Since the hybrid parents of the ICRs had limited diversity on maternal lineage, paternal lineage was concluded as the major contributor to the observed divergence and population differentiation. ICRs developed from certain hybrids were more genetically distinct than other hybrids. Even with the moderate variability, ICRs could be considered as a potential source of fertility restoration in hybrid development because of their distinct population structure and the full complement of restorer genes they contained. ICR lines with high per se performance can be utilized in hybrid rice development by estimating their combining ability.