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Biomedical subjects

Maria Angela Diroma

Publications and source records attributed to Maria Angela Diroma.

4 recordsLinked to original sources

Genomic signatures of dairy adaptation in Saccharomyces cerevisiae from traditional Yaghnob goat-cheese fermentation.

The growing interest in studying Saccharomyces cerevisiae strains from previously unexplored niches is greatly expanding our understanding of this yeast's ecology and evolution. While strains involved in alcoholic fermentation are the most studied, S. cerevisiae has also been isolated from milk fermentations and their products, suggesting a potential evolutionary specialization for dairy environments. These fermentations are characterized by the predominant presence of lactose, a carbon source that S. cerevisiae cannot metabolize directly but can exploit through the enzymatic activity of co-occurring microorganisms that convert lactose into fermentable substrates, such as glucose and galactose. In this study, we analyzed S. cerevisiae strains isolated from an unexplored and remote niche: traditional goat fermented milk produced by the Yaghnob people, an ethnically and geographically partly isolated population living in the Upper Zarafshan area of the Republic of Tajikistan. Comparative analyses with published S. cerevisiae genomes positioned the Yaghnob strains at the base of the phylogenetic dairy clade. These strains revealed distinctive coding sequences and strain-specific single-nucleotide variants present in all Yaghnob strains but absent from the other 1,053 strains analyzed. Further investigation of variants in key genes involved in galactose metabolism provided insights into the genomic and protein-level evolution of Yaghnob strains, uncovering unique genomic signatures of adaptation to the dairy environment.

Saccharomyces cerevisiae

HPRC2: A human pangenome reference with near-complete coverage of common genetic variation.

A pangenome reference overcomes the inherent limitation of any individual reference genome by integrating the variation present in a population. We present the Human Pangenome Reference Consortium's (HPRC) Release 2 (HPRC2), an openly available, second phase pangenome that is an approximately fivefold expansion in genome number over HPRC Release 1 (HPRC1) and measurable improvement in genome completeness, contiguity, and accuracy. Selecting samples with a principled algorithm prioritising common variant coverage, HPRC2 contributes 460 haplotypes that together capture over 99% of common variation observed in the All of Us Research Program v8 cohort. Combining high-coverage long and ultra-long reads with modern assemblers and polishers, we produce thousands of telomere-to-telomere (T2T) chromosomes, and relative to HPRC1 halve the number of structurally unreliable regions as well as individual base errors per haplotype. We complement the assemblies with whole genome multiple alignments and gene annotations, and derive formal pangenome coordinate systems for addressing off-reference variation, demonstrating that individual human genomes contain more than one hundred thousand variants not succinctly described with respect to existing reference genomes. We also present the first matched long-read backed pantranscriptome and panepigenome at this scale, provide continuous local-ancestry estimates spanning every genome, and outline a host of new tools and applications that leverage the pangenome resource for improved genomics analysis.

Journal Article

ERGA-BGE reference genome of the Eurasian Woodcock ( Scolopax rusticola), a game bird species with isolated populations of conservation interest.

The reference genome of the Eurasian Woodcock ( Scolopax rusticola) is an important resource to investigate population structure across the wide breeding range of this iconic game species and the conservation status of specific management units, such as the isolated Macaronesian populations. The genome sequence was assembled into 45 contiguous chromosomal pseudomolecules and 2 sex chromosomes (W and Z). This chromosome-level assembly encompasses 1.2 Gb, composed of 1,613 contigs and 935 scaffolds, with contig and scaffold N50 values of 5.9 Mb and 34.2 Mb, respectively.

Aves

Whole Genome Sequencing Reveals How Plasticity and Genetic Differentiation Underlie Sympatric Morphs of Arctic Charr.

Salmonids have a remarkable ability to form sympatric morphs after postglacial colonisation of freshwater lakes. These morphs often differ in morphology, feeding and spawning behaviour. Here, we explored the genetic basis of morph differentiation in Arctic charr (n = 283) by first establishing a high-quality reference genome and then using this in whole genome sequencing of distinct morphs present in two Norwegian and two Icelandic lakes. The four lakes represent the spectrum of genetic differentiation between morphs from one lake with no genetic differentiation between morphs, implying phenotypic plasticity, to two lakes with locus-specific genetic differentiation, implying incomplete reproductive isolation, and one lake with strong genome-wide divergence consistent with complete reproductive isolation. As many as 12 putative inversions ranging from 0.45 to 3.25 Mbp in size segregated among the four morphs present in one lake, Thingvallavatn, and these contributed significantly to the genetic differentiation among morphs. None of the putative inversions were found in any of the other lakes, but there were cases of partial haplotype sharing in similar morph contrasts in other lakes. Our findings are consistent with a highly polygenic basis of morph differentiation with population-specific selection on alleles linked to the development of similar morph phenotypes. The results support a model where morph differentiation is first established through phenotypic plasticity, leading to niche expansion and separation. This may be followed by gradual development of reproductive isolation, locus-specific differentiation and eventually complete reproductive isolation and genome-wide divergence.

Whole Genome Sequencing