Karyotype differentiation and male meiosis in European clades of the spider genus Pholcus (Araneae, Pholcidae)
Result description
Haplogyne araneomorphs are a diverse spider clade. Their karyotypes are usually predominated by biarmed (i.e., metacentric and submetacentric) chromosomes and have a specific sex chromosome system, X1X2Y. These features are probably ancestral for haplogynes. Nucleolus organizer regions (NORs) spread fre-quently from autosomes to sex chromosomes in these spiders. This study focuses on pholcids (Pholcidae), a highly diverse haplogyne family. Despite considerable recent progress in pholcid cytogenetics, knowledge on many clades remains insufficient including the most species-rich pholcid genus, Pholcus Walckenaer, 1805. To characterize the karyotype differentiation of Pholcus in Europe, we compared karyotypes, sex chromosomes, NORs, and male meiosis of seven species [P. alticeps Spassky, 1932; P. creticus Senglet, 1971; P. dentatus Wunderlich, 1995; P. fuerteventurensis Wunderlich, 1992; P. phalangioides (Fuesslin, 1775); P. opilionoides (Schrank, 1781); P. silvai Wunderlich, 1995] representing the dominant species groups in this region. The species studied show several features ancestral for Pholcus, namely the 2n male = 25, the X1X2Y system, and a karyotype predominated by biarmed chromosomes. Most taxa have a large acro-centric NOR-bearing pair, which evolved from a biarmed pair by a pericentric inversion. In some lineages, the acrocentric pair reverted to biarmed. Closely related species often differ in the morphology of some chromosome pairs, probably resulting from pericentric inversions and/or translocations. Such rearrange-ments have been implicated in the formation of reproductive barriers. While the X1 and Y chromosomes retain their ancestral metacentric morphology, the X2 chromosome shows a derived (acrocentric or sub-telocentric) morphology. Pairing of this element is usually modified during male meiosis. NOR patterns are very diverse. The ancestral karyotype of Pholcus contained five or six terminal NORs including three X chromosome-linked loci. The number of NORs has been frequently reduced during evolution. In the Macaronesian clade, there is only a single NOR-bearing pair. Sex chromosome-linked NORs are lost in Madeiran species and in P. creticus. Our study revealed two cytotypes in the synanthropic species P. phalan-gioides (Madeiran and Czech), which differ by their NOR pattern and chromosome morphology. In the Czech cytotype, the large acrocentric pair was transformed into a biarmed pair by pericentric inversion.
Keywords
Synspermiataspeciationsex chromosomerDNANORinversionhaplogyne
The result's identifiers
Result code in IS VaVaI
Alternative codes found
RIV/49777513:23420/22:43971392
Result on the web
https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=n4DcFqqLhF
DOI - Digital Object Identifier
Alternative languages
Result language
angličtina
Original language name
Karyotype differentiation and male meiosis in European clades of the spider genus Pholcus (Araneae, Pholcidae)
Original language description
Haplogyne araneomorphs are a diverse spider clade. Their karyotypes are usually predominated by biarmed (i.e., metacentric and submetacentric) chromosomes and have a specific sex chromosome system, X1X2Y. These features are probably ancestral for haplogynes. Nucleolus organizer regions (NORs) spread fre-quently from autosomes to sex chromosomes in these spiders. This study focuses on pholcids (Pholcidae), a highly diverse haplogyne family. Despite considerable recent progress in pholcid cytogenetics, knowledge on many clades remains insufficient including the most species-rich pholcid genus, Pholcus Walckenaer, 1805. To characterize the karyotype differentiation of Pholcus in Europe, we compared karyotypes, sex chromosomes, NORs, and male meiosis of seven species [P. alticeps Spassky, 1932; P. creticus Senglet, 1971; P. dentatus Wunderlich, 1995; P. fuerteventurensis Wunderlich, 1992; P. phalangioides (Fuesslin, 1775); P. opilionoides (Schrank, 1781); P. silvai Wunderlich, 1995] representing the dominant species groups in this region. The species studied show several features ancestral for Pholcus, namely the 2n male = 25, the X1X2Y system, and a karyotype predominated by biarmed chromosomes. Most taxa have a large acro-centric NOR-bearing pair, which evolved from a biarmed pair by a pericentric inversion. In some lineages, the acrocentric pair reverted to biarmed. Closely related species often differ in the morphology of some chromosome pairs, probably resulting from pericentric inversions and/or translocations. Such rearrange-ments have been implicated in the formation of reproductive barriers. While the X1 and Y chromosomes retain their ancestral metacentric morphology, the X2 chromosome shows a derived (acrocentric or sub-telocentric) morphology. Pairing of this element is usually modified during male meiosis. NOR patterns are very diverse. The ancestral karyotype of Pholcus contained five or six terminal NORs including three X chromosome-linked loci. The number of NORs has been frequently reduced during evolution. In the Macaronesian clade, there is only a single NOR-bearing pair. Sex chromosome-linked NORs are lost in Madeiran species and in P. creticus. Our study revealed two cytotypes in the synanthropic species P. phalan-gioides (Madeiran and Czech), which differ by their NOR pattern and chromosome morphology. In the Czech cytotype, the large acrocentric pair was transformed into a biarmed pair by pericentric inversion.
Czech name
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Czech description
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Classification
Type
Jimp - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
—
OECD FORD branch
10613 - Zoology
Result continuities
Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
S - Specificky vyzkum na vysokych skolach
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2022
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Comparative Cytogenetics
ISSN
1993-0771
e-ISSN
1993-078X
Volume of the periodical
16
Issue of the periodical within the volume
4
Country of publishing house
RU - RUSSIAN FEDERATION
Number of pages
25
Pages from-to
185-209
UT code for WoS article
000885469700001
EID of the result in the Scopus database
2-s2.0-85142298171
Basic information
Result type
Jimp - Article in a specialist periodical, which is included in the Web of Science database
OECD FORD
Zoology
Year of implementation
2022