@article{fdi:010046231,
  title = {2{L}a chromosomal inversion enhances thermal tolerance of {A}nopheles gambiae larvae},
  author = {{R}occa, {K}. {A}. {C}. and {G}ray, {E}. {M}. and {C}ostantini, {C}arlo and {B}esansky, {N}. {J}.},
  editor = {},
  language = {{ENG}},
  abstract = {{B}ackground: {T}he mosquito {A}nopheles gambiae is broadly distributed throughout sub-{S}aharan {A}frica and this contributes to making it the most efficient vector of malaria on the continent. {T}he pervasiveness of this species is hypothesized to originate in local adaptations facilitated by inversion polymorphisms. {O}ne inversion, named 2{L}a, is strongly associated with aridity clines in {W}est and {C}entral {A}frica: while 2{L}a is fixed in arid savannas, the 2{L}(+a) arrangement is predominantly found in the rainforest. {A}bility to survive high temperature exposure is an essential component of aridity tolerance, particularly in immature stages that are restricted to shallow puddles. {T}oward deciphering the role of the 2{L}a inversion in local adaptation, the present investigation focused on variation in larval and pupal thermo-tolerance in two populations dissimilar solely in 2{L}a arrangement. {M}ethods: {A} laboratory colony of {A}. gambiae that is polymorphic for 2{L}a but standard for all other known inversions was used to create 2 homokaryotypic populations (2{L}(+a) and 2{L}a). {T}he survival of 4(th) instar larvae and pupae from both populations was then tested following exposure to thermal stress with and without prior heat hardening. {R}esults: {L}arvae responded identically to a 40 degrees {C} heat stress, with about 50% of larvae dying after 1.5-2 h and few larvae surviving a 3 h stress. {W}hen heat hardened prior to the thermal stress, thermo-tolerance of both larval populations increased, with 2{L}a 24 h survival significantly exceeding that of 2{L}(+a). {P}upae were generally more thermo-tolerant than larvae, although 2{L}a pupae were less so than 2{L}(+a). {H}eat hardening had no positive effect on pupal thermo-tolerance. {C}onclusion: {T}he increased thermo-tolerance observed in 2{L}a larvae following heat hardening suggests higher responsiveness (i.e., thermal sensitivity) of the inverted karyotype. {B}y responding more drastically to the heat shock, 2{L}a larvae are better equipped to resist the potentially lethal temperatures that occur in arid habitats. {T}he lower survival of 2{L}a pupae compared with 2{L}(+a) may reflect the cost of this sensitivity, whereby the thermal resistance mechanisms prevent successful completion of metamorphosis. {T}he costs and benefits of thermal resistance are discussed in light of the climates characterizing either end of the 2{L}a frequency cline.},
  keywords = {},
  booktitle = {},
  journal = {{M}alaria {J}ournal},
  volume = {8},
  numero = {},
  pages = {147},
  ISSN = {1475-2875},
  year = {2009},
  DOI = {10.1186/1475-2875-8-147},
  URL = {https://www.documentation.ird.fr/hor/fdi:010046231},
}