A molecular characterization of the charismatic Faroe house mouse

Publication Type:Journal Article
Year of Publication:2011
Authors:Alibardi, L, Jones, EP, Jensen, J-K, Magnussen, EĐF, Gregersen, N, Hansen, HS, Searle, JB
Journal:Acta Zoologica
Volume:92
Pagination:187-200
Date Published:2011
ISBN Number:1095-8312
Keywords:Mus musculus
Abstract:

Alibardi L. 2011. Histology, ultrastructure, and pigmentation in the horny scales of growing crocodilians. —Acta Zoologica (Stockholm) 92: 187–200. The present morphological study describes the color of hatchling, juvenile, and adult crocodilian skin and the origin of its pigmentation. In situ hybridization and immunostaining indicate that crocodilian scales grow as an expansion of the proliferating epidermis of the hinge region that form thin lateral rings. In more central areas of growing scales, new epidermal layers contribute to increase the thickness of the stratum corneum. The dark pigmentation and color pattern derive from the different distribution of epidermal and dermal chromatophores. The more intensely pigmented stripes, irregular patches and dot-like spots, especially numerous in dorsal scales, derive from the incorporation of the eumelanosomes of epidermal melanocytes in differentiating beta cells of the epidermis. Dermal melanophores, mainly localized in the loose upper part of the dermis, also contribute to the formation of the dark or gray background of crocodilian scales. The eumelanosomes of dermal melanophores determine the darkening of the skin pattern in association with the epidermal melanocytes. Iridophores are infrequent, while xantophores are present in the species analyzed with a sparse distribution in the superficial dermis among melanophores. The presence of xantophores and of the few iridophores in areas where epidermal melanocytes are absent appear to determine the brown or the light yellow-orange background observed among the darker regions of crocodilian scales.Faroe house mice are a ‘classic’ system of rapid and dramatic morphological divergence highlighted by J. S. Huxley during the development of the Modern Synthesis. In the present study, we characterize these charismatic mice using modern molecular techniques, examining specimens from all Faroe islands occupied by mice. The aims were to classify the mice within the modern house mouse taxonomy (i.e. as either Mus musculus domesticus or Mus musculus musculus) using four molecular markers and a morphological feature, and to examine the genetic diversity and possible routes of colonization using mitochondrial (mt) control region DNA sequences and microsatellite data (15 loci). Mice on the most remote islands were characterized as M. m. domesticus and exhibited exceptionally low genetic diversity, whereas those on better connected islands were more genetically diverse and had both M. m. musculus and M. m. domesticus genetic elements, including one population which was morphologically M. m. musculus-like. The mtDNA data indicate that the majority of the mice had their origins in south-western Norway (or possibly southern Denmark/northern Germany), and probably arrived with the Vikings, earlier than suggested by Huxley. The M. m. musculus genetic component appears to derive from recent mouse immigration from Denmark. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102, 471–482.

URL:http://dx.doi.org/10.1111/j.1095-8312.2010.01597.x
Taxonomic name: 
Thu, 2014-03-20 12:43 -- admin
https://secure.gravatar.com/avatar/5ade1b012674ce3dd941e2ea5dd15cc1.jpg?d=https%3A//mammals.indianbiodiversity.org/sites/all/modules/contrib/gravatar/avatar.png&s=100&r=G
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith