vavilovВавиловский журнал генетики и селекцииVavilov Journal of Genetics and Breeding2500-3259Institute of Cytology and Genetics of Siberian Branch of the RAS10.18699/VJ17.245vavilov-938Research ArticleГЕНЕТИКА ЖИВОТНЫХANIMAL GENETICSСинапсис и рекомбинация аутосом и половых хромосом у двух видов крачек (Sternidae, Charadriiformes, Aves)Synapsis and recombination of autosomes and sex chromosomes in two terns (Sternidae, Charadriiformes, Aves)ЛисачевА. П.LisachovA. P.

Новосибирск

Novosibirsk

lisachev@bionet.nsc.ruМалиновскаяЛ. П.MalinovskayaL. P.

Новосибирск

Novosibirsk

l.malinovskaia@g.nsu.ruДрузякаА. В.DruzyakaA. V.

Новосибирск

Novosibirsk

БородинП. М.BorodinP. M.

Новосибирск

Novosibirsk

ТоргашеваА. А.TorgashevaA. A.

Новосибирск

Novosibirsk

Федеральное государственное бюджетное научное учреждение «Федеральный исследовательский центр Институт цитологии и генетики Сибирского отделения Российской академии наук»РоссияInstitute of Cytology and Genetics SB RASRussian FederationФедеральное государственное бюджетное научное учреждение «Федеральный исследовательский центр Институт цитологии и генетики Сибирского отделения Российской академии наук»; Федеральное государственное автономное образовательное учреждение высшего образования «Новосибирский национальный исследовательский государственный университет»РоссияInstitute of Cytology and Genetics SB RAS; Novosibirsk State UniversityRussian FederationФедеральное государственное бюджетное учреждение науки «Институт систематики и экологии животных Сибирского отделения Российской академии наук»РоссияInstitute of Animal Systematics and Ecology SB RASRussian Federation201722042017212259268Copyright © Лисачев А.П., Малиновская Л.П., Друзяка А.В., Бородин П.М., Торгашева А.А., 20172017Лисачев А.П., Малиновская Л.П., Друзяка А.В., Бородин П.М., Торгашева А.А.Lisachov A.P., Malinovskaya L.P., Druzyaka A.V., Borodin P.M., Torgasheva A.A.This work is licensed under a Creative Commons Attribution 4.0 License.https://vavilov.elpub.ru/jour/article/view/938

Интенсивность мейотической рекомбинации и закономерности распределения точек кроссинговера вдоль хромосом значительно варьируют между видами животных, в том числе близкородственными. Предложено несколько гипотез об адаптивном значении этих различий и их эволюции. Высказаны предположения о том, что рекомбинационные характеристики видов обусловлены филогенетической историей видов и их экологией. Однако большая часть исходных данных получена на млекопитающих, у которых характеристики рекомбинации находятся под влиянием значительной кариологической изменчивости. В этой связи изучение характеристик рекомбинации у таксонов с более стабильными кариотипами, таких как рептилии и птицы, представляется актуальным. В данной работе использовали метод флуоресцентной иммунолокализации белка бокового элемента синаптонемного комплекса (SYCP3), белков центромеры и белка мисматч-репарации MLH1, маркирующего сайты кроссинговера, на препаратах распластанных профазных ооцитов для изучения особенностей синапсиса и рекомбинации у двух видов птиц – черной крачки (Chlidonias niger) и речной крачки (Sterna hirundo). Мы впервые охарактеризовали кариотип Ch. niger (2n = 74, FN = 94), уточнили описание кариотипа S. hirundo (2n = 68, FN = 90) и идентифициро- вали предположительные перестройки, отличающие кариотипы данных видов друг от друга. Обнаружено, что черная и речная крачки достоверно отличаются по среднему числу кроссоверов на клетку (53.0±4.2 у черной и 44.1±5.0 у речной крачек) и по распределению кроссоверов на гомологичных хромосомах. Показано, что различия по числу кроссоверов обусловлены различиями в длине синаптонемных комплексов – суммарной длине аутосомных комплексов и длине индивидуальных бивалентов. Было установлено, что на число обменов и различия в их распределении влияют хромосомные перестройки: различие рекомбинационных характеристик между перестроенными гомеологами было выше, чем между неперестроенными. Мы описали особенности синапсиса гетероморфных Z- и W-хромосом, локализовали псевдоаутосомный район и оценили его физический размер. Выяснено, что несмотря на перестройки аутосом, отличающие друг от друга указанные виды, строение и синаптические характеристики половых хромосом не изменились за 9 млн лет, прошедших со времени дивергенции родов Sterna и Chlidonias.

The frequency of recombination and the patterns of crossover site distribution along the chromosomes vary considerably among animal species, including closely related species. Several hypotheses concerning the adaptive value and evolution of these variations were proposed. It was supposed that the recombination patterns of the species’ genomes are influenced by their phylogenetic history and ecology. However, most original data were obtained from mammals. The mammals show high karyological variability, which strongly influences the recombination patterns. Therefore it is important to study recombination rate and distribution in more karyologically stable taxa, such as reptiles and birds. We used immunolocalization of SYCP3, the protein of the lateral element of the synaptonemal complex (SC), centromere proteins and the mismatch-repair protein MLH1, which is associated with the recombination nodules, at the synaptonemal complex spreads of prophase oocytes of two tern species, black tern (Chlidonias niger) and common tern (Sterna hirundo). We first described the karyotype of Ch. niger (2n = 74, FN= 94) and identified suggestive rearrangements by which its karyotype differs from that of S. hirundo (2n = 68, FN = 90). We found that these species significantly differed by the numbers of the MLH1 foci per cell (Ch. niger: 53.0±4.2; S. hirundo: 44.1±5.0). We showed that the difference in the crossover numbers per cell was determined by the difference in the SC length (total and of individual bivalents) and by chromosomal rearrangements, which also influenced the distributions of crossover sites along the chromosomes. The difference in recombination patterns was higher between the rearranged homeologues than between the non-rearranged ones. We investigated the synaptic patterns of the heteromor phic Z and W chromosomes, localized the pseudoautosomal regions and estimated their lengths. In spite of several autosomal rearrangements, which differentiate these species, the structure and synaptic patterns of the sex chromosomes have not changed over 9 MY, which have passed since the moment of divergence between the genera Sterna and Chlidonias.

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The authors declare that there are no conflicts of interest present.