Hall KW et al. (2016), Proteinaceous Pheromone Homologs Identified fro...

XB-ART-52540

PLoS One 2016 Jan 01;112:e0146851. doi: 10.1371/journal.pone.0146851.

Show Gene links Show Anatomy links

Proteinaceous Pheromone Homologs Identified from the Cloacal Gland Transcriptome of a Male Axolotl, Ambystoma mexicanum.

Hall KW , Eisthen HL , Williams BL .

???displayArticle.abstract???
Pheromones play an important role in modifying vertebrate behavior, especially during courtship and mating. Courtship behavior in urodele amphibians often includes female exposure to secretions from the cloacal gland, as well as other scent glands. The first vertebrate proteinaceous pheromone discovered, the decapeptide sodefrin, is a female attracting pheromone secreted by the cloacal gland of male Cynops pyrrhogaster. Other proteinaceous pheromones in salamanders have been shown to elicit responses from females towards conspecific males. The presence and levels of expression of proteinaceous pheromones have not been identified in the family Ambystomatidae, which includes several important research models. The objective of this research was therefore to identify putative proteinaceous pheromones from male axolotls, Ambystoma mexicanum, as well as their relative expression levels. The results indicate that axolotls possess two different forms of sodefrin precursor-like factor (alpha and beta), as well as a putative ortholog of plethodontid modulating factor. The beta form of sodefrin precursor-like factor was amongst the most highly expressed transcripts within the cloacal gland. The ortholog of plethodontid modulating factor was expressed at a level equivalent to the beta sodefrin precursor-like factor. The results are from a single male axolotl; therefore, we are unable to assess how representative our results may be. Nevertheless, the presence of these highly expressed proteinaceous pheromones suggests that male axolotls use multiple chemical cues to attract female conspecifics. Behavioral assays would indicate whether the putative protein pheromones elicit courtship activity from female axolotls.

???displayArticle.pubmedLink??? 26885665
???displayArticle.pmcLink??? PMC4757389
???displayArticle.link??? PLoS One

???attribute.lit??? ???displayArticles.show???

References [+] :

Altschul, Basic local alignment search tool. 1990, Pubmed

	Fig 1. Pictorial representation of the process to assemble a transcriptome.First, RNA was extracted from the cloacal gland and HiSeq Illumina reads were created. The sequence reads were parsed and filtered for quality and removal of adaptor sequences (blue). Next, de novo assembly was generated and the transcripts were filtered based upon BLAST hits and redundant contigs were removed (red). Reads were mapped back to contigs, genes were annotated, and gene ontology was applied using BLAST and BLAST2GO (green). Finally, an analysis of the assembly and the quantity and distribution of transcripts was performed.
	Fig 2. Distribution of sequence lengths from the final transcriptome assembly.The x-axis indicates sequence sizes from 200 bp to ≥ 5000 bp with a bin size of 100; the y-axis indicates the number of transcripts for a given sequence length bin. Most (60%) of the final assembly sequences range between 200 399 nucleotides in length; however, more than 6% of transcripts are longer than 2000 bp.
	Fig 3. BLASTx or BLASTp top-hit species distribution generated from matches to the X. tropicalis, UniProtKB, and UniRef90 protein databases.
	Fig 4. Distribution of GO annotations among biological processes, cellular components and molecular function.
	Fig 5. Level two GO classifications of final assembly contigs.The results are summarized in three main categories: biological process (blue), cellular component (red), and molecular function (green). The x-axis indicates the number of genes in a category on a log scale. The y-axis on the left indicates the specific category of genes in that main category.
	Fig 6. Comparison of deduced amino acid sequences for alpha SPF, beta SPF, and PMF aligned using ClustalW Multiple Alignment.Alpha SPF sequence from Notophthalmus viridescens aligned with the most highly expressed homolog, contig c7051_g1_i1 which was expressed at 35 TPM. Beta SPF sequence from Lissotriton vulgaris aligned with the most highly expressed homolog, contig c3350_g1_i1 which was expressed at 1477 TPM. PMF sequence from Plethodon shermani aligned with the most highly expressed homolog, contig c2860_g1_i1 which was expressed at 1336 TPM.
	Fig 7. Putative full length homologs of alpha SPF, beta SPF, PMF, and AFP.
	Fig 8. Frequency distribution of expression levels of putative genes expressed in transcripts per million (TPM).The x-axis indicates expression levels from 0 TPM to 100 TPM with a bin size of 1 and from 101 to ≥ 6200 with a bin size of 100; the y-axis indicates the number of transcripts for a given TPM bin.