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  - González-Fortes, Gloria M.
A1  - Kolbe, Ben
A1  - Fernandes, Daniel
A1  - Meleg, Ioana N.
A1  - Garcia-Vazquez, Ana
A1  - Pinto-Llona, Ana C.
A1  - Constantin, Silviu
A1  - de Torres, Trino J.
A1  - Ortiz, Jose E.
A1  - Frischauf, Christine
A1  - Rabeder, Gernot
A1  - Hofreiter, Michael
A1  - Barlow, Axel
T1  - Ancient DNA reveals differences in behaviour and sociality between brown bears and extinct cave bears
JF  - Molecular ecology
N2  - Ancient DNA studies have revolutionized the study of extinct species and populations, providing insights on phylogeny, phylogeography, admixture and demographic history. However, inferences on behaviour and sociality have been far less frequent. Here, we investigate the complete mitochondrial genomes of extinct Late Pleistocene cave bears and middle Holocene brown bears that each inhabited multiple geographically proximate caves in northern Spain. In cave bears, we find that, although most caves were occupied simultaneously, each cave almost exclusively contains a unique lineage of closely related haplotypes. This remarkable pattern suggests extreme fidelity to their birth site in cave bears, best described as homing behaviour, and that cave bears formed stable maternal social groups at least for hibernation. In contrast, brown bears do not show any strong association of mitochondrial lineage and cave, suggesting that these two closely related species differed in aspects of their behaviour and sociality. This difference is likely to have contributed to cave bear extinction, which occurred at a time in which competition for caves between bears and humans was likely intense and the ability to rapidly colonize new hibernation sites would have been crucial for the survival of a species so dependent on caves for hibernation as cave bears. Our study demonstrates the potential of ancient DNA to uncover patterns of behaviour and sociality in ancient species and populations, even those that went extinct many tens of thousands of years ago.
KW  - ancient DNA
KW  - extinction
KW  - homing
KW  - sociality
KW  - Ursus arctos
KW  - Ursus spelaeus
Y1  - 2016
U6  - https://doi.org/10.1111/mec.13800
SN  - 0962-1083
SN  - 1365-294X
VL  - 25
SP  - 4907
EP  - 4918
PB  - Wiley-Blackwell
CY  - Hoboken
ER  -