Reduced gene expression and missense mutations in the transporter protein SLC45A2 in a hypopigmented Egyptian rousette fruit bat (Rousettus aegyptiacus)
Data files
Oct 22, 2025 version files 5.07 MB
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README.md
3.57 KB
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Rousettus_nCounter_raw.csv
3.19 KB
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SLC45A2_BAT_isoforms.fasta
27.36 KB
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SLC45A2_BAT_transcriptomes.fas
114.88 KB
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SLC45A2_SangerBats.zip
4.92 MB
Abstract
Oculocutaneous albinism—characterised by absent or decreased melanin in the skin, eyes, and hair—often co-occurs with sensory, skin, and immunity disorders. The genetic basis of albinism in humans is complex, with many loci implicated in multiple forms of the disorder. Less is known about the underlying genetic causes of albinism and leucism in other species, and cross-species studies of the molecular correlates of hypopigmentation could highlight common and conserved pathways underlying mammalian pigmentation disorders. We characterise the putative causal loci of reduced pigmentation in an Egyptian fruit bat (Rousettus aegyptiacus) that displayed features indicative of albinism. Despite albino or leucistic individuals having been reported in >100 bat species, the associated genetic backgrounds have not previously been studied. We used a digital gene expression panel to quantify mRNA levels in wing membrane samples of four candidate pigmentation genes in the focal albino fruit bat and control individuals. Significantly reduced SLC45A2 mRNA expression was found in the albino compared to five bats with typical colouration. Additionally, intraspecific sequence analyses of the albino bat SLC45A2 coding sequence identified two missense mutations, E18A and Q298R, the former of which was private to the albino bat. Position 18 of SLC45A2 was otherwise found to be highly conserved across 60 bat species and has not been previously linked to human albinism. By identifying SLC45A2 as the likely contributing locus, our results also indicate further support for the necessity of genetic testing for the reliable categorisation of hypopigmented animals as either albino or leucistic.
Dataset DOI: 10.5061/dryad.bcc2fqzsf
Description of the data and file structure
This dataset contains data generated and used in analyses to test for the underlying genetic cause of hypopigmentation in an individual Egyptian rousette fruit bat (Rousettus aegyptiacus). The data includes gene expression values for four genes known to be associated with oculocutaneous albinism (OCA) in mammals, and sequence data for a single gene (the transporter protein SLC45A2) generated by Sanger sequencing from R. aegyptiacus bats. To place the sequence variants detected in the hypopigmented bat in a wider evolutionary context, SLC45A2 coding sequences were also extracted from genomes and transcriptomes in 60 bat species and compared.
Files and variables
File: SLC45A2_SangerBats.zip
Description: This zipped folder contains the raw Sanger sequencing files (.ab1, .scf, and .seq) produced for two R. aegyptiacus bats (CPN010 – hypopigmented and CPN006 – typical colouration). All seven exons of the SLC45A2 gene were sequenced as identified by E1–E7 in the file names. Sanger sequencing was performed in both directions: forward (FOR) and reverse (REV).
File: SLC45A2_BAT_transcriptomes.fas
Description: SLC45A2 coding sequence nucleotide alignment generated for 60 bat species and Homo sapiens. Sequences were extracted from genomes, transcriptomes and obtained from Sanger sequencing. Sequences were aligned with Clustal X and manually edited where necessary, (‘?’ – missing data, ‘-’ – alignment gap). See Table S5 of the accompanying paper for data source information.
File: SLC45A2_BAT_isoforms.fasta
Description: SLC45A2 coding sequence nucleotide alignment of the two alternative isoforms retrieved from transcriptomes from across multiple individuals of Artibeus jamaicensis, Phyllops falcatus, and Pteronotus parnellii pusillus, (‘?’ – missing data, ‘-’ – alignment gap).
File: Rousettus_nCounter_raw.csv
Description: Raw nCounter gene expression values for four genes associated with oculocutaneous albinism (OCA) in mammals (TYR, OCA2, TYRP1, and SLC45A2) and three housekeeping genes (ABCF1, EIF2B4, and GUSB). Values for eight negative (A–H) and six positive (A–F) controls are also provided. Expression values were measured across six bats (CPN003, CPN004, CPN005, CPN006, CPN008 and CPN010) from tissue sampled at four points from the wing (WL1 – leading 1, WL2 – leading 2, WM3 – mid-wing 3, and WT4 – wing tip 4) and one sample of skin from the arm (SA). Note: in the above table NA refers to ‘not applicable’, as positive and negative controls do not have corresponding gene accession numbers.
Variables
- Probe_Name: This is the name of each probe for which expression data was collected. Names consist of the gene under study (TYR, OCA2, TYRP1, SLC45A2, ABCF1, EIF2B4, and GUSB), and the dataset (Rousettus). Negative controls begin with ‘NEG_’ and positive controls ‘POS_’.
- Accession#: This variable provides the Rousettus aegyptiacus genomic sequence accession number that was used to design probes for the seven genes included in the study.
- Class_Name: Designates whether the probe corresponds to either an ‘Endogenous’ gene, a ‘Housekeeping’ gene, a ‘Negative’ or a ‘Positive’ control.