Islands as Time Capsules for Genetic Diversity Conservation: The Case of the Giglio Island Mouflon

The use of multidisciplinary approaches of investigation including biological, biogeographical, historical, morphological, and genetic analysis, can be useful in identifying and preserving biodiversity. The present study focuses on the characterisation and conservation of a mouflon population (Ovis gmelini musimon) from the Mediterranean island of Giglio. Here we provide the first molecular data on the Giglio population and compare it with mouflons from Sardinia, Elba, and Corsica using both nuclear and mitochondrial markers. Our results suggest that the Giglio mouflon harbours genetic variability likely of Sardinian origin but not represented in the current Sardinian mouflon diversity. Although not presenting the typical characteristics of an invasive alien species, the Giglio mouflon is being subjected to eradication through culling or trapping and surgical sterilization. The molecular evidence we report highlights that such actions are causing the irremediable loss of ancestral genetic variants of the genus Ovis. Finally, we highlight how a multidisciplinary approach is necessary to aid the conservation and management of the anthropochorous populations of Mediterranean mammals

Genomic signatures of adaptive introgression from European mouflon into domestic sheep

Mouflon (Ovis aries musimon) became extinct from mainland Europe after the Neolithic, but remnant populations from the Mediterranean islands of Corsica and Sardinia have been used for reintroductions across Europe since the 19th-century. Mouflon x sheep hybrids are larger-bodied than mouflon, potentially showing increased male reproductive success, but little is known about genomic levels of admixture, or about the adaptive significance of introgression between resident mouflon and local sheep breeds. Here we analysed Ovine medium-density SNP array genotypes of 92 mouflon from six geographic regions, along with data from 330 individuals of 16 domestic sheep breeds. We found lower levels of genetic diversity in mouflon than in domestic sheep, consistent with past bottlenecks in mouflon. Introgression signals were bidirectional and affected most mouflon and sheep populations, being strongest in one Sardinian mouflon population. Developing and using a novel approach to identify chromosomal regions with consistent introgression signals, we infer adaptive introgression from mouflon to domestic sheep related to immunity mechanisms, but not in the opposite direction. Further, we infer that Soay and Sarda sheep carry introgressed mouflon alleles involved in bitter taste perception and/or innate immunity. Our results illustrate the potential for adaptive introgression even among recently diverged populations

Characterization of four novel variants of goat β^A-globin gene

Four novel alleles of the adult β-globin gene of Capra hircus were observed in an extended study on hemoglobin polymorphism in goat breeds living in the island of Sardinia. Nucleotide sequencing showed that one of these alleles is due to a 2 bp substitution at codon 125 (CT→GAG, G, "Leu→Glu). Two substitutions, the silent CT T→CTC for Leu at codon 78 and the conservative A AG→AG G (Lys→Arg) at codon 104, are shared by the other three alleles, two of them having additional mutations, which suggests a common origin. The allele we provisionally called the βY shares four out of five amino acid substitutions, together with the same polymorphisms in the IVSII, we observed previously in the rather common βE gene. This evidence allowed the origin of the βE gene to be better characterized. The data increase to seven the number of alleles at the goat βA-globin locus characterized thus far at the molecular level. A simplified nomenclature for the increasing number of goat β-globin alleles is presented

The C→G transition in the α2-globin gene of a normal αα-chromosome is responsible for the Hb G-Philadelphia variant in Sardinians

Sequencing of α-globin genes of 18 Sardinian heterozygotes for the Hb G-Philadelphia [α68(E17)Asn→Lys] variant, with four active α genes and circulating level of the variant of about 27%, showed the AAC→AAG change at codon 68 of the α 2-globin gene (αGα / αα). Two heterozygotes with level of about 37% were the carriers of the same mutation on the same α2 gene, and of the α2α1 hybrid gene, because of the 3.7-kb deletion, in trans (αGα /−α 3.7). In Black people, the same C→G mutation occurs on the hybrid gene (−αG3.7), whereas in Caucasians the Lys for Asn change is because of the C→A transversion occurring on the α2 gene of a normal αα arrangement. The identification of the C→G mutation on the normal αα chromosome points to an undescribed genotype for this rather common variant, which is probably because of the high rate of recombination between the duplicated α-globin genes

First mtDNA Sequences and Body Measurements for Rattus norvegicus from the Mediterranean Island of Cyprus

Invasive species are the primary driver of island taxa extinctions and, among them, those belonging to the genus Rattus are considered as the most damaging. The presence of black rat (Rattus rattus) on Cyprus has long been established, while that of brown rat (Rattus norvegicus) is dubious. This study is the first to provide molecular and morphological data to document the occurrence of R. norvegicus in the island of Cyprus. A total of 223 black rats and 14 brown rats were collected. Each sample was first taxonomically attributed on the basis of body measurements and cranial observations. Four of the specimens identified as R. norvegicus and one identified as R. rattus were subjected to molecular characterization in order to corroborate species identification. The analyses of the mitochondrial control region were consistent with morphological data, supporting the taxonomic identification of the samples. At least two maternal molecular lineages for R. norvegicus were found in Cyprus. The small number of brown rats collected in the island, as well as the large number of samples of black rats retrieved in the past years might be an indication that the distribution of R. norvegicus is still limited into three out of the six districts of Cyprus

Hb F-Emirates [^Gγ59(E3)Lys→Glu] observed in a family of Sardinian ancestry and characterized by DNA sequencing

Hb F-Emirates [Gγ59(E3)Lys→Glu] was first described in a newborn from the United Arab Emirates. Here we describe the occurrence of this variant in a family of Sardinian ancestry. Direct DNA sequencing analysis of the selectively amplified Gγ gene shows that the AAA→GAA transition, corresponding to a Lys→Glu substitution, is responsible for this abnormal hemoglobin (Hb). Our observation indicates a multiple origin of the mutation. In order to facilitate future studies at the level of population genetics, the structure of the entire Gγ gene that carries the mutation was assessed and compared with that of normal Gγ genes

Islands as Time Capsules for Genetic Diversity Conservation: The Case of the Giglio Island Mouflon

The use of multidisciplinary approaches of investigation including biological, biogeographical, historical, morphological, and genetic analysis, can be useful in identifying and preserving biodiversity. The present study focuses on the characterisation and conservation of a mouflon population (Ovis gmelini musimon) from the Mediterranean island of Giglio. Here we provide the first molecular data on the Giglio population and compare it with mouflons from Sardinia, Elba, and Corsica using both nuclear and mitochondrial markers. Our results suggest that the Giglio mouflon harbours genetic variability likely of Sardinian origin but not represented in the current Sardinian mouflon diversity. Although not presenting the typical characteristics of an invasive alien species, the Giglio mouflon is being subjected to eradication through culling or trapping and surgical sterilization. The molecular evidence we report highlights that such actions are causing the irremediable loss of ancestral genetic variants of the genus Ovis. Finally, we highlight how a multidisciplinary approach is necessary to aid the conservation and management of the anthropochorous populations of Mediterranean mammals

A New unstable variant of the fetal hemoglobin HBG2 gene: Hb F-Turritana [Gγ64(E8)GlyAsp, HBG2:c.194G>A] found in cis to the Hb F-Sardinia gene [Aγ(E19)IleThr, HBG1:c.227T>C]

A new variant of the fetal hemoglobin (Hb) was observed in a newborn baby subjected to phototherapy due to jaundice, by means of electrophoretic and chromatographic techniques. The variant Hb resulted unstable by the isopropanol stability test. After HBG2 gene sequencing, the G to A transversion at codon 64, position eight of the E helix, was found, which corresponds to the Asp for Gly amino acid substitution. The new variant was called Hb F-Turritana [Gγ64(E8)Gly → Asp, HBG2:c.194G>A]. Incoming aspartic acid residue, bulky and negatively charged, may be responsible for alteration of the heme pocket steric configuration and for instability. The new abnormal HBG2 gene was found to be associated in cis with the mutated HBG1 gene, which characterizes the Hb F-Sardinia [Aγ (E19)IleThr, HBG1:c.227T>C] variant

Two abnormal fetal hemoglobins found in the Sardinian population: the new Hb F-Osilo [^Aγ119(GH2)Gly→Ser, GGC > AGC] and Hb F-Paulinia [^Gγ80(EF4)Asp→Tyr, GAT > TAT] aready described in the Brazilian population

Two healthy newborns, heterozygous for two different Y-globin chain mutations, were observed during an electrophoretic screening for hemoglobinopathies in Sassari, North Sardinia (Italy). The variants were characterized by reversed phase high performance liquid chromatography (HPLC) and sequencing of amplified Y-globin genes. One of the two abnormalities was a novel Aγchain variant and the tetramer was named Hb F-Osilo [Aγ119(GH2)Gly→Ser]. The other was a Gγ chain variant, Hb F-Paulinia [Gγ80(EF4)Asp→Tyr], already described in a Brazilian baby of African ancestry. No functional studies could be performed

A Novel -72 (T→A) β-Promoter Mutation Causing Slightly Elevated HbA2 in a Vietnamese Heterozygote

We report a novel β+-thalassemia mutation found in a Vietnamese family. The molecular defect T→A lies at -72 of the β-globin gene promoter, within the conserved CCAAT box. The index case was a 5-year-old child having red blood cells indices close to normal and slightly increased level of HbA2 (3.96%). The expression of the mutated β allele was inferred by luciferase reporter assay in K562 cells. The β -72 determinant is the eighth β-thalassemic mutation identified in Vietnam and it was not previously reported in any population. The absence of homozygous or compound heterozygous states did not allow us to precisely predict either its clinical impact or its relevance in management programs. Our results further underline the importance of identifying and characterizing new or rare β+-thalassemic alleles in carrier screening and prenatal diagnosis