TY  - GEN
A1  - Zancolli, Giulia
A1  - Baker, Timothy G.
A1  - Barlow, Axel
A1  - Bradley, Rebecca K.
A1  - Calvete, Juan J.
A1  - Carter, Kimberley C.
A1  - de Jager, Kaylah
A1  - Owens, John Benjamin
A1  - Price, Jenny Forrester
A1  - Sanz, Libia
A1  - Scholes-Higham, Amy
A1  - Shier, Liam
A1  - Wood, Liam
A1  - Wüster, Catharine E.
A1  - Wüster, Wolfgang
T1  - Is hybridization a source of adaptive venom variation in rattlesnakes?
BT  - a test, using a crotalus scutulatus × viridis hybrid zone in southwestern New Mexico
T2  - Toxins
N2  - Venomous snakes often display extensive variation in venom composition both between and within species. However, the mechanisms underlying the distribution of different toxins and venom types among populations and taxa remain insufficiently known. Rattlesnakes (Crotalus, Sistrurus) display extreme inter-and intraspecific variation in venom composition, centered particularly on the presence or absence of presynaptically neurotoxic phospholipases A2 such as Mojave toxin (MTX). Interspecific hybridization has been invoked as a mechanism to explain the distribution of these toxins across rattlesnakes, with the implicit assumption that they are adaptively advantageous. Here, we test the potential of adaptive hybridization as a mechanism for venom evolution by assessing the distribution of genes encoding the acidic and basic subunits of Mojave toxin across a hybrid zone between MTX-positive Crotalus scutulatus and MTX-negative C. viridis in southwestern New Mexico, USA. Analyses of morphology, mitochondrial and single copy-nuclear genes document extensive admixture within a narrow hybrid zone. The genes encoding the two MTX subunits are strictly linked, and found in most hybrids and backcrossed individuals, but not in C. viridis away from the hybrid zone. Presence of the genes is invariably associated with presence of the corresponding toxin in the venom. We conclude that introgression of highly lethal neurotoxins through hybridization is not necessarily favored by natural selection in rattlesnakes, and that even extensive hybridization may not lead to introgression of these genes into another species.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 443 
KW  - adaptation
KW  - Crotalus
KW  - evolution
KW  - hybridization
KW  - introgression
KW  - Mojave toxin
KW  - molecular evolution
KW  - venom
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-407595
ER  - 
TY  - JOUR
A1  - Zancolli, Giulia
A1  - Baker, Timothy G.
A1  - Barlow, Axel
A1  - Bradley, Rebecca K.
A1  - Calvete, Juan J.
A1  - Carter, Kimberley C.
A1  - de Jager, Kaylah
A1  - Owens, John Benjamin
A1  - Price, Jenny Forrester
A1  - Sanz, Libia
A1  - Scholes-Higham, Amy
A1  - Shier, Liam
A1  - Wood, Liam
A1  - Wüster, Catharine E.
A1  - Wüster, Wolfgang
T1  - Is Hybridization a Source of Adaptive Venom Variation in Rattlesnakes? A Test, Using a Crotalus scutulatus x viridis Hybrid Zone in Southwestern New Mexico
JF  - Toxins
N2  - Venomous snakes often display extensive variation in venom composition both between and within species. However, the mechanisms underlying the distribution of different toxins and venom types among populations and taxa remain insufficiently known. Rattlesnakes (Crotalus, Sistrurus) display extreme inter-and intraspecific variation in venom composition, centered particularly on the presence or absence of presynaptically neurotoxic phospholipases A2 such as Mojave toxin (MTX). Interspecific hybridization has been invoked as a mechanism to explain the distribution of these toxins across rattlesnakes, with the implicit assumption that they are adaptively advantageous. Here, we test the potential of adaptive hybridization as a mechanism for venom evolution by assessing the distribution of genes encoding the acidic and basic subunits of Mojave toxin across a hybrid zone between MTX-positive Crotalus scutulatus and MTX-negative C. viridis in southwestern New Mexico, USA. Analyses of morphology, mitochondrial and single copy-nuclear genes document extensive admixture within a narrow hybrid zone. The genes encoding the two MTX subunits are strictly linked, and found in most hybrids and backcrossed individuals, but not in C. viridis away from the hybrid zone. Presence of the genes is invariably associated with presence of the corresponding toxin in the venom. We conclude that introgression of highly lethal neurotoxins through hybridization is not necessarily favored by natural selection in rattlesnakes, and that even extensive hybridization may not lead to introgression of these genes into another species.
KW  - adaptation
KW  - Crotalus
KW  - evolution
KW  - hybridization
KW  - introgression
KW  - Mojave toxin
KW  - molecular evolution
KW  - venom
Y1  - 2016
U6  - https://doi.org/10.3390/toxins8060188
SN  - 2072-6651
VL  - 8
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Wuster, Wolfgang
A1  - Chirio, Laurent
A1  - Trape, Jean-Francois
A1  - Ineich, Ivan
A1  - Jackson, Kate
A1  - Greenbaum, Eli
A1  - Barron, Cesar
A1  - Kusamba, Chifundera
A1  - Nagy, Zoltan T.
A1  - Storey, Richard
A1  - Hall, Cara
A1  - Wuster, Catharine E.
A1  - Barlow, Axel
A1  - Broadley, Donald G.
T1  - Integration of nuclear and mitochondrial gene sequences and morphology reveals unexpected diversity in the forest cobra (Naja melanoleuca) species complex in Central and West Africa (Serpentes: Elapidae)
JF  - Zootaxa : an international journal of zootaxonomy ; a rapid international journal for animal taxonomists
N2  - Cobras are among the most widely known venomous snakes, and yet their taxonomy remains incompletely understood, particularly in Africa. Here, we use a combination of mitochondrial and nuclear gene sequences and morphological data to diagnose species limits within the African forest cobra, Naja (Boulengerina) melanoleuca. Mitochondrial DNA sequences reveal deep divergences within this taxon. Congruent patterns of variation in mtDNA, nuclear genes and morphology support the recognition of five separate species, confirming the species status of N. subfulva and N. peroescobari, and revealing two previously unnamed West African species, which are described as new: Naja (Boulengerina) guineensis sp. nov. Broadley, Trape, Chirio, Ineich & Wuster, from the Upper Guinea forest of West Africa, and Naja (Boulengerina) savannula sp. nov. Broadley, Trape, Chirio & Wuster, a banded form from the savanna-forest mosaic of the Guinea and Sudanian savannas of West Africa. The discovery of cryptic diversity in this iconic group highlights our limited understanding of tropical African biodiversity, hindering our ability to conserve it effectively.
KW  - Integrative taxonomy
KW  - Africa
KW  - Naja melanoleuca
KW  - Naja guineensis sp nov.
KW  - Naja savannula sp nov.
KW  - Elapidae
KW  - systematics
Y1  - 2018
U6  - https://doi.org/10.11646/zootaxa.4455.1.3
SN  - 1175-5326
SN  - 1175-5334
VL  - 4455
IS  - 1
SP  - 68
EP  - 98
PB  - Magnolia Press
CY  - Auckland
ER  -