Y-STR diversity and sex-biased gene flow among Caribbean populations Tanya M. Simms a , Marisil R. Wright a , Emanuel Martinez a , Maria Regueiro a , Quinn McCartney b , Rene J. Herrera a, ⁎ a Department of Molecular and Human Genetics, College of Medicine, Florida International University, Miami, FL 33199, USA b Royal Bahamas Police Force, Forensic Laboratory, P. O. Box N-458, Nassau, Bahamas abstract article info Article history: Accepted 10 November 2012 Available online 21 November 2012 Keywords: Bahamas Haiti Jamaica New World Y-STR Phylogenetic analyses In the present study, we report, for the first time, the allele and haplotype frequencies of 17 Y-STR (Y-filer) loci in the populations of Haiti, Jamaica and the Bahamas (Abaco, Eleuthera, Exuma, Grand Bahama, Long Island and New Providence). This investigation was undertaken to assess the paternal genetic structure of the abovementioned Caribbean islands. A total of 607 different haplotypes were identified among the 691 males examined, of which 537 (88.5%) were unique. Haplotype diversities (HD) ranged from 0.989 in Long Island to 1.000 in Grand Bahama, with limited haplotype sharing observed among these Caribbean collec- tions. Discriminatory capacity (DC) values were also high, ranging from 79.1% to 100% in Long Island and Grand Bahama, respectively, illustrating the capacity of this set of markers to differentiate between patrilineal re- lated individuals within each population. Phylogenetic comparison of the Bahamian, Haitian and Jamaican groups with available African, European, East Asian and Native American populations reveals strong genetic ties with the continental African collections, a finding that corroborates our earlier work using autosomal STR and Y-chromosome binary markers. In addition, various degrees of sex-biased gene flow exhibiting dispropor- tionately higher European paternal (as compared to autosomal) influences were detected in all Caribbean islands genotyped except for Abaco and Eleuthera. We attribute the presence or absence of asymmetric gene flow to unique, island specific demographic events and family structures. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Y-chromosomal short tandem repeats (Y-STRs) are sequences that occur concurrently throughout the non-recombining portion of the Y-chromosome (NRY) and consist of 2–7 base pair motifs reiterated head to tail in tandem (Kashyap et al., 2004). Their selective neutral- ity, reproducibility, lack of recombination and high power of discrim- ination as well as the large number of available loci make them an attractive molecular tool for assessing phylogenetic relationships among patrilineal related human populations (Jobling et al., 1997; Gill et al., 2001; Gusmão and Carracedo, 2003; Rowold and Herrera, 2003). These hypervariable markers are also valuable for forensic casework in that they allow for male-specific DNA amplification, which is pertinent in sexual assault cases where the female portion typically overwhelms the male component (Butler, 2003), as well as for determination of the number of male contributors in gang rapes (Prinz et al., 2001; Butler, 2003). Our group and other investigators have observed various patterns of sex-biased gene flow in a number of ex-colonial populations through- out the Americas (Carvajal-Carmona et al., 2000; Seielstad, 2000; Gonçalves et al., 2008; Mendizabal et al., 2008; Núñez et al., 2012). These findings prompted us to undertake this more comprehensive study involving additional Caribbean populations in an attempt to as- certain how widespread asymmetrical heritage was and the impact sex-biased gene flow had on populations in the region. In addition, given that substantial allelic frequency differences have been reported using autosomal STR and Y-chromosomal SNP (single nucleotide poly- morphism) markers in the Caribbean basin (Simms et al., 2008, 2010, 2011, 2012a, 2012b), investigations on population-specific Y-STR varia- tion for the various islands throughout the region is warranted. There- fore, in order to shed light on these issues, we have genotypes 17 Y-STR loci in several Caribbean populations, including Haiti, Jamaica and the Bahamas (i.e., Abaco, Eleuthera, Exuma, Grand Bahama, Long Is- land and New Providence), and compared them to African, European, Gene 516 (2013) 82–92 Abbreviations: DC, discriminatory capacity; dbmax, maximum diversity between two populations; dwmin, minimum diversity within the population, FUH, fraction of unique haplotypes; HD, haplotype diversity; n, sample size; ng/μl, nanograms per mi- croliter; MDS, multidimensional scaling; mbmin, minimum matching probability be- tween two populations; mwmax, maximum matching probability within the population; mwmin, minimum matching probability within the population; NRY, non-recombining portion of the Y-chromosome; SNP, single nucleotide polymor- phism; STR, short tandem repeat; US, United States; YHRD, Y-STR haplotype reference database; Y-SNP, Y-chromosomal single nucleotide polymorpshism; Y-STR, Y-chromo- some short tandem repeat. ⁎ Corresponding author at: Department of Molecular and Human Genetics, College of Medicine, Florida International University, University Park, OE 304, Miami, FL 33199, USA. Tel.: +1 305 348 1258; fax: +1 305 348 1259. E-mail address: herrerar@fiu.edu (R.J. Herrera). 0378-1119/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.gene.2012.11.006 Contents lists available at SciVerse ScienceDirect Gene journal homepage: www.elsevier.com/locate/gene