RESUMO
The criteria used by previous authors to define colour aberrancies of snakes, particularly albinism, are varied and terms have widely been used ambiguously. The aim of this work was to review genetically based aberrant colour morphs of wild Neotropical snakes and associated terminology. We compiled a total of 115 cases of conspicuous defective expressions of pigmentations in snakes, including melanin (black/brown colour), xanthins (yellow), and erythrins (red), which involved 47 species of Aniliidae, Boidae, Colubridae, Elapidae, Leptotyphlopidae, Typhlopidae, and Viperidae. Most of them were hypopigmented conditions, mainly amelanism, but also anerythrism, axanthism, hypomelanism, leucism, piebaldism, and albinism (total absence of pigments). Hyperpigmented aberrancies were mostly melanism and xanthism, plus a few instances of erythrism. No associations with diurnality and fossorial behaviour were observed, neither for blanched nor hyperpigmented aberrancies. A discussion of the terms most commonly used for wild snakes is provided, with an account of cases of aberrant colourations in other South American reptiles. Finally, we propose a simple classification framework of wild snake colour aberrancies based on predominant dorsal colour and eye pigmentation for the adoption of a standardized terminology, which may be applicable to other squamates and chelonians. We advocate the use of a more accurate terminology in the scientific literature that would avoid the use of confusing terms like “partial albinism”.
RESUMO
BACKGROUND: Species adaptation to laboratory conditions is a special case of domestication that has modified model organisms phenotypically and genetically. The characterisation of these changes is crucial to understand how this variation can affect the outcome of biological experiments. Yet despite the wide use of laboratory animals in biological research, knowledge of the genetic diversity within and between different strains and populations of some animal models is still scarce. This is particularly the case of the Mexican axolotl, which has been bred in captivity since 1864. RESULTS: Using gene expression data from nine different projects, nucleotide sequence variants were characterised, and distinctive genetic background of the experimental specimens was uncovered. This study provides a catalogue of thousands of nucleotide variants along predicted protein-coding genes, while identifying genome-wide differences between pigment phenotypes in laboratory populations. CONCLUSIONS: Awareness of the genetic variation could guide a better experimental design while helping to develop molecular tools for monitoring genetic diversity and studying gene functions in laboratory axolotls. Overall, this study highlights the cross-taxa utility that transcriptomic data might have to assess the genetic variation of the experimental specimens, which might help to shorten the journey towards reproducible research.
Assuntos
Ambystoma mexicanum , Domesticação , Ambystoma mexicanum/genética , Animais , Variação Genética , Genoma , México , FenótipoRESUMO
Dentre os crocodilianos com ocorrência no Brasil, o Caiman crocodilus (Linnaeus, 1758) é a espécie de maior frequência, porém sua presença em estudos científicos restringe-se a levantamentos faunísticos, na maioria das vezes. O leucismo, também conhecido como albinismo parcial, é uma anomalia cromática ainda pouco conhecida. Indivíduos portadores dos genes que condicionam a doença apresentam ausência de pigmentação em uma parte ou em todo o corpo, porém os olhos não apresentam alteração. O objetivo deste trabalho foi realizar o primeiro registro de Caiman crocodilus com leucismo no mundo.(AU)
Among crocodilians in Brazil, Caiman crocodilus (Linnaeus, 1758) is the most frequent species, but its presence in scientific studies is mostly restricted to faunal surveys. Leukism, also known as partial albinism, is a still little known chromatic anomaly. Individuals with genes that condition the disease present no pigmentation in one part or in the whole body, but the eyes did not change. The objective of this work was to perform the first record of Caiman crocodilus with leucismo in the world.(AU)
Assuntos
Animais , Piebaldismo/veterinária , Monofenol Mono-Oxigenase , Jacarés e Crocodilos , Animais SelvagensRESUMO
Dentre os crocodilianos com ocorrência no Brasil, o Caiman crocodilus (Linnaeus, 1758) é a espécie de maior frequência, porém sua presença em estudos científicos restringe-se a levantamentos faunísticos, na maioria das vezes. O leucismo, também conhecido como albinismo parcial, é uma anomalia cromática ainda pouco conhecida. Indivíduos portadores dos genes que condicionam a doença apresentam ausência de pigmentação em uma parte ou em todo o corpo, porém os olhos não apresentam alteração. O objetivo deste trabalho foi realizar o primeiro registro de Caiman crocodilus com leucismo no mundo.(AU)
Among crocodilians in Brazil, Caiman crocodilus (Linnaeus, 1758) is the most frequent species, but its presence in scientific studies is mostly restricted to faunal surveys. Leukism, also known as partial albinism, is a still little known chromatic anomaly. Individuals with genes that condition the disease present no pigmentation in one part or in the whole body, but the eyes did not change. The objective of this work was to perform the first record of Caiman crocodilus with leucismo in the world.(AU)
Assuntos
Animais , Piebaldismo/veterinária , Monofenol Mono-Oxigenase , Jacarés e Crocodilos , Animais SelvagensRESUMO
The present study reports a case of leucism in South American Lungfish Lepidosiren paradoxa captured in Corrientes, Argentina. It was observed a change in cutaneous pigmentation, and it was concluded that it was leucism and not albinism, since there was a decrease of tegumentary melanin pigment and normal pigmentation in the retina.
Assuntos
Animais , Peixes/genética , Pigmentação da Pele/genética , ArgentinaRESUMO
The present study reports a case of leucism in South American Lungfish Lepidosiren paradoxa captured in Corrientes, Argentina. It was observed a change in cutaneous pigmentation, and it was concluded that it was leucism and not albinism, since there was a decrease of tegumentary melanin pigment and normal pigmentation in the retina.(AU)
Assuntos
Animais , Peixes/genética , Pigmentação da Pele/genética , ArgentinaRESUMO
Leucism is the lack or reduction in pigmentation in the most or parts of the body, but not in the eyes and body extremities. It is extremely rare in primates and has never been reported for Callithrix, a genus endemic to Brazil. We searched for individuals of Callithrix jacchus and C. penicillata with pigmentation anomalies in a systematic survey of three protected areas in the Atlantic Forest, within museum collections in Brazil, and opportunistically during field studies. Since 2008, we have recorded 8 individuals with leucism in small urban and periurban forest patches. Four were from native populations of C. penicillata in Cerrado savannahs and of C. jacchus in the Caatinga xeric scrubland, and 4 were from populations of hybrids between C. jacchus and C. penicillata in invaded areas in the coastal Atlantic Forest. We found no pigmentation abnormalities in museum specimens. We hypothesize that the observed leucism may be linked to inbreeding within the native range, but to hybridization within the invaded range, and discuss the likely ecological consequences to leucistic individuals.
Assuntos
Callithrix/fisiologia , Hibridização Genética , Pigmentação , Animais , Brasil , Callithrix/anatomia & histologia , Callithrix/genética , Feminino , Espécies Introduzidas , MasculinoRESUMO
Abstract: Coloration anomalies are mainly genetically-based disorders in which body pigmentation is either reduced (hypopigmentation) or produced in excess (melanism), in parts or the totality of the body. Cases of hypopigmentation have been documented in many neotropical mammals, including the tayra (Eira barbara Linnaeus, 1758). We expand the account of anomalous coloration occurrence presenting new registers of hypopigmented tayras in Brazil. Data was collected during a mammal survey carried out in three agricultural landscapes within the Cerrado domain in the northeast of the state of São Paulo. We obtained two kinds of records of hypopigmented tayras, one from direct sighting and the other from a camera-trap. We discuss the likely implications of this conspicuous coloration to tayras and highlight some possibilities of study.
Resumo: Colorações anômalas são desordens geralmente de origem genética, em que a pigmentação do corpo é reduzida (hipopigmentação) ou excessiva (melanismo), em partes ou totalmente. Casos de hipopigmentação já foram documentados em muitos mamíferos neotropicais, incluindo a irara (Eira barbara Linnaeus, 1758). Nós expandimos os relatos de ocorrência de colorações anômalas apresentando novos registros de iraras hipopigmentadas no Brasil. Dados foram coletados durante um levantamento de mamíferos em três paisagens agrícolas no domínio do Cerrado no nordeste do estado de São Paulo. Obtivemos dois tipos de registros de iraras hipopigmentadas, sendo um por avistamento e outro por armadilhas fotográficas. Nós discutimos possíveis implicações ecológicas dessa coloração em iraras e sugerimos novas possibilidades de estudos.
RESUMO
Abstract The occurrence of anomalous coloration (albinism, leucism and melanism) in mammals is a rare phenomenon in nature, but this phenomenon has been reported for several species of mammals. In this study, we report on the occurrence of leucism in Eira barbara by examining three road-killed individuals and two sightings of live animals in Reserva Particular do Patrimônio Natural Santuário do Caraça, southeastern Brazil. In addition, we examined tayra specimens housed in mammal collections from Brazil and USA. The animals found dead and those sighted had a whitish yellow fur on the body and head, resulting in lighter coloration than the coloring pattern commonly observed in tayras. Despite these lighter color pattern, the specimens showed parts of soft tissue, such as iris and the skin, with pigmentation very similar to that present in individuals with the typical color pattern. This set of factors indicates the specimens recorded were in fact leucistic and not albino. Among the specimens examined in the scientific collections, we found nine individuals from different localities that presented the whitish yellow color pattern. Some studies attribute the higher frequency of cases of leucism due to small populations and / or with some mechanism of reproductive isolation. Thus, analysis of the genetic variability of populations containing individuals with such characteristics should be considered. On the other hand, the occurrence of polymorphic color phenotype in tayras indicates that hypotheses related to the fixation of recessive characteristics, or on possible environmental adaptive advantages of these phenotypes can be tested.
Resumo A ocorrência de coloração anômala (albinismo, leucísmo e melanismo) em mamíferos é um fenômeno raro na natureza, mas ela tem sido relatada para diversas espécies. Neste trabalho nós relatamos a ocorrência de leucísmo em Eira barbara por meio do exame de três indivíduos encontrados mortos atropelados por veículos e pela visualização direta de indivíduos vivos na Reserva Particular do Patrimônio Natural Santuário do Caraça, sudeste brasileiro. Em adição, nós consultamos coleções de mamíferos em museus do Brasil e dos Estados Unidos da América. Os animais encontrados mortos e os avistados apresentavam pelagem amarela esbranquiçada no corpo e na cabeça, resultando em uma coloração muito mais clara que o padrão de coloração comumente observado em iraras. Apesar deste padrão de coloração mais claro, os espécimes apresentavam partes do tecido mole, tais como a íris e a pele, com pigmentação muito semelhante àquela presente em indivíduos com padrão de coloração típico da espécie. Este conjunto de fatores indicou que os espécimes registrados eram de fato leucísticos e não albinos. Dentre os espécimes examinados nas coleções científicas, nós encontramos nove indivíduos de diferentes localidades que apresentavam o padrão de coloração esbranquiçado. Alguns estudos atribuem a frequência elevada de casos de leucísmo a pequenas populações e / ou com algum mecanismo de isolamento reprodutivo. Dessa forma, análises da variabilidade genética de populações contendo indivíduos com essas características devem ser consideradas. Por outro lado, a ocorrência de fenótipos de coloração polimórficos em iraras indica que hipóteses podem ser testadas tanto com relação à fixação de caraterísticas recessivas, quanto sobre possíveis vantagens adaptativas ambientais desses fenótipos.
RESUMO
The aim of this communication is to report the first documented case of leucism in Artibeus phaeotis from Guatemala. The bat was captured in Laguna del Tigre National Park, Petén, in northern Guatemala, while we were conducting a bat sampling in the area. Leucism is a condition rarely observed in nature, which is characterized by the partial or total depigmentation of fur; in this case the specimen is distinguished by a depigmentation in the ventral side of the body.(AU)
Assuntos
Animais , Quirópteros , Pigmentação da Pele , MelatoninaRESUMO
The aim of this communication is to report the first documented case of leucism in Artibeus phaeotis from Guatemala. The bat was captured in Laguna del Tigre National Park, Petén, in northern Guatemala, while we were conducting a bat sampling in the area. Leucism is a condition rarely observed in nature, which is characterized by the partial or total depigmentation of fur; in this case the specimen is distinguished by a depigmentation in the ventral side of the body.
Assuntos
Animais , Melatonina , Pigmentação da Pele , QuirópterosRESUMO
In bats, there are several reports on pigmentation disorders (albinism, leucism, and melanism), but only thirteen of them deal with leucism in Phyllostomidae. The goal of this paper is to describe leucism in one of the least-known Neotropical frugivorous bat species, Artibeus amplus, in an Andean location of Venezuela. This is the first report for the species, the second for Venezuela, the sixth for the genus Artibeus, and the fourteenth for Phyllostomidae.
Assuntos
Animais , Mutação/genética , Pigmentação/genética , Quirópteros , MelaninasRESUMO
In bats, there are several reports on pigmentation disorders (albinism, leucism, and melanism), but only thirteen of them deal with leucism in Phyllostomidae. The goal of this paper is to describe leucism in one of the least-known Neotropical frugivorous bat species, Artibeus amplus, in an Andean location of Venezuela. This is the first report for the species, the second for Venezuela, the sixth for the genus Artibeus, and the fourteenth for Phyllostomidae.(AU)
Assuntos
Animais , Quirópteros , Pigmentação/genética , Mutação/genética , MelaninasRESUMO
This study reports the first occurrence of partial albinism in two species of Ariidae: Genidens barbus and Genidens planifrons from an estuary of Southern Brazil. Possible causes of the simultaneous occurrence of three specimens with partial albinism are discussed, including random genetic alterations, chronic contamination effects and small effective population size, which may favor the expression of the recessive albino gene.
RESUMO
Anomalous colourations occur in many tropical vertebrates. However, they are considered rare in wild populations, with very few records for the majority of animal taxa. We report two new cases of anomalous colouration in mammals. Additionally, we compiled all published cases about anomalous pigmentation registered in Neotropical mammals, throughout a comprehensive review of peer reviewed articles between 1950 and 2010. Every record was classified as albinism, leucism, piebaldism or eventually as undetermined pigmentation. As results, we report the new record of a leucistic specimen of opossum (Didelphis sp.) in southern Brazil, as well as a specimen of South American fur seal (Arctocephalus australis) with piebaldism in Uruguay. We also found 31 scientific articles resulting in 23 records of albinism, 12 of leucism, 71 of piebaldism and 92 records classified as undetermined pigmentation. Anomalous colouration is apparently rare in small terrestrial mammals, but it is much more common in cetaceans and michrochiropterans. Out of these 198 records, 149 occurred in cetaceans and 30 in bats. The results related to cetaceans suggest that males and females with anomolous pigmentation are reproductively successful and as a consequence their frequencies are becoming higher in natural populations. In bats, this result can be related to the fact these animals orient themselves primarily through echolocation, and their refuges provide protection against light and predation. It is possible that anomalous colouration occurs more frequently in other Neotropical mammal orders, which were not formally reported. Therefore, we encourage researchers to publish these events in order to better understand this phenomenon that has a significant influence on animal survival.(AU)
Colorações anômalas ocorrem em muitos vertebrados tropicais. Entretanto, estas são consideradas raras em populações selvagens, havendo poucos registros para a maioria dos táxons. Reportam-se, neste estudo, dois novos casos de coloração anômala em mamíferos. Além disso, por meio de uma extensa revisão bibliográfica, foram compilados os casos publicados sobre coloração anômala em mamíferos neotropicais entre 1950 e 2010. Cada registro foi classificado como albinismo, leucismo, piebaldismo ou, eventualmente, como coloração indeterminada. Como resultados, reportou-se o registro de um espécime leucístico de gambá (Didelphis sp.) no sul do Brasil e de um espécime de lobo-marinho sul-americano (Arctocephalus australis) com piebaldismo no norte do Uruguai. Também foram analisados 31 artigos científicos, resultando em 23 registros de albinismo, 12 de leucismo, 71 de piebaldismo e 92 registros classificados como de pigmentação indeterminada. A coloração anômala aparentemente é rara em pequenos mamíferos terrestres, mas é muito mais comum em cetáceos e microquirópteros. Dos 198 registros encontrados, 149 ocorreram em cetáceos e 30 em morcegos. No caso dos cetáceos, este resultado sugere que machos e fêmeas com este padrão anômalo de pigmentação são reprodutivamente exitosos e, consequentemente, sua frequência está aumentando nas populações naturais. Com relação aos morcegos, este fenômeno pode estar relacionado ao fato de estes animais orientarem-se primariamente por meio de ecolocalização e seus refúgios oferecerem proteção contra luz e predação. É possível que a coloração anômala ocorra mais frequentemente em outras ordens de mamíferos neotropicais, as quais não foram formalmente reportadas. Desta forma, mostra-se importante encorajar os pesquisadores a publicar estes eventos em vida selvagem para um melhor entendimento deste fenômeno, que tem influência significativa na sobrevivência destes organismos.(AU)
Assuntos
Animais , Transtornos da Pigmentação , Mamíferos/anormalidades , Didelphis , Otárias , Piebaldismo , Albinismo , Hipopigmentação , Didelphis/anormalidades , Otárias/anormalidadesRESUMO
Anomalous colourations occur in many tropical vertebrates. However, they are considered rare in wild populations, with very few records for the majority of animal taxa. We report two new cases of anomalous colouration in mammals. Additionally, we compiled all published cases about anomalous pigmentation registered in Neotropical mammals, throughout a comprehensive review of peer reviewed articles between 1950 and 2010. Every record was classified as albinism, leucism, piebaldism or eventually as undetermined pigmentation. As results, we report the new record of a leucistic specimen of opossum (Didelphis sp.) in southern Brazil, as well as a specimen of South American fur seal (Arctocephalus australis) with piebaldism in Uruguay. We also found 31 scientific articles resulting in 23 records of albinism, 12 of leucism, 71 of piebaldism and 92 records classified as undetermined pigmentation. Anomalous colouration is apparently rare in small terrestrial mammals, but it is much more common in cetaceans and michrochiropterans. Out of these 198 records, 149 occurred in cetaceans and 30 in bats. The results related to cetaceans suggest that males and females with anomolous pigmentation are reproductively successful and as a consequence their frequencies are becoming higher in natural populations. In bats, this result can be related to the fact these animals orient themselves primarily through echolocation, and their refuges provide protection against light and predation. It is possible that anomalous colouration occurs more frequently in other Neotropical mammal orders, which were not formally reported. Therefore, we encourage researchers to publish these events in order to better understand this phenomenon that has a significant influence on animal survival.
Colorações anômalas ocorrem em muitos vertebrados tropicais. Entretanto, estas são consideradas raras em populações selvagens, havendo poucos registros para a maioria dos táxons. Reportam-se, neste estudo, dois novos casos de coloração anômala em mamíferos. Além disso, por meio de uma extensa revisão bibliográfica, foram compilados os casos publicados sobre coloração anômala em mamíferos neotropicais entre 1950 e 2010. Cada registro foi classificado como albinismo, leucismo, piebaldismo ou, eventualmente, como coloração indeterminada. Como resultados, reportou-se o registro de um espécime leucístico de gambá (Didelphis sp.) no sul do Brasil e de um espécime de lobo-marinho sul-americano (Arctocephalus australis) com piebaldismo no norte do Uruguai. Também foram analisados 31 artigos científicos, resultando em 23 registros de albinismo, 12 de leucismo, 71 de piebaldismo e 92 registros classificados como de pigmentação indeterminada. A coloração anômala aparentemente é rara em pequenos mamíferos terrestres, mas é muito mais comum em cetáceos e microquirópteros. Dos 198 registros encontrados, 149 ocorreram em cetáceos e 30 em morcegos. No caso dos cetáceos, este resultado sugere que machos e fêmeas com este padrão anômalo de pigmentação são reprodutivamente exitosos e, consequentemente, sua frequência está aumentando nas populações naturais. Com relação aos morcegos, este fenômeno pode estar relacionado ao fato de estes animais orientarem-se primariamente por meio de ecolocalização e seus refúgios oferecerem proteção contra luz e predação. É possível que a coloração anômala ocorra mais frequentemente em outras ordens de mamíferos neotropicais, as quais não foram formalmente reportadas. Desta forma, mostra-se importante encorajar os pesquisadores a publicar estes eventos em vida selvagem para um melhor entendimento deste fenômeno, que tem influência significativa na sobrevivência destes organismos.
Assuntos
Animais , Feminino , Humanos , Masculino , Didelphis , Otárias , Transtornos da Pigmentação/epidemiologia , Albinismo/epidemiologia , Piebaldismo/epidemiologiaRESUMO
Aberrant colorations resulting from colour pigment deficiencies are commonly described in the bat literature. In this study we report the first leucistic piebald of Phyllostomus discolor (Wagner, 1843) by describing an individual captured in Central Amazonia, Brazil, that presented a distinct white patch on its body but normally pigmented eyes. This is the first report of hypo-pigmentism in the species, but also in the genus.(AU)
Assuntos
Animais , Quirópteros , Demografia , Piebaldismo/veterinária , Fenômenos Genéticos , Cor de Olho , PigmentaçãoRESUMO
A female specimen was captured in a rock shelter located within a anthropogenic fragment of Atlantic Forest in the northeastern Brazilian state of Sergipe. This specimen revealed leucism restricted to the pelage of the body, which was completely white, whereas the eyes, wings, legs, ears, snout, and nasal leaf were all coloured normally. The female was apparently well integrated into the group, ostensibly healthy, of normal size and carrying a late-term fetus.(AU)
Assuntos
Animais , Piebaldismo/veterinária , Transtornos da Pigmentação/veterinária , Pigmentação , Quirópteros , Fenômenos Genéticos , Cor de OlhoRESUMO
A female specimen was captured in a rock shelter located within a anthropogenic fragment of Atlantic Forest in the northeastern Brazilian state of Sergipe. This specimen revealed leucism restricted to the pelage of the body, which was completely white, whereas the eyes, wings, legs, ears, snout, and nasal leaf were all coloured normally. The female was apparently well integrated into the group, ostensibly healthy, of normal size and carrying a late-term fetus.
Assuntos
Animais , Piebaldismo/veterinária , Pigmentação , Quirópteros , Transtornos da Pigmentação/veterinária , Cor de Olho , Fenômenos GenéticosRESUMO
Aberrant colorations resulting from colour pigment deficiencies are commonly described in the bat literature. In this study we report the first leucistic piebald of Phyllostomus discolor (Wagner, 1843) by describing an individual captured in Central Amazonia, Brazil, that presented a distinct white patch on its body but normally pigmented eyes. This is the first report of hypo-pigmentism in the species, but also in the genus.