Corresponding author: Mukhamed Kh. Karmokov (
Academic editor: V. Golygina
The study presents data on the karyotype characteristics and features of chromosomal polymorphism of
Karmokov MKh (2018) Karyotype characteristics and chromosomal polymorphism of
There are a great number of publications that mention the name of
Keyl & Keyl (1959) described the karyotype of
The aim of the work was to present the description of karyotype characteristics and chromosomal polymorphism of
We used fourth instar larvae of
Collections sites of
Collection sites and number of analyzed
Localities | Population abbreviation | Collection sites | Collection date | Number of specimens |
---|---|---|---|---|
European population | NL-NT-NT | The Netherlands | 07.1998 | 16 |
Siberian populations | RU-OMS-IR | Omskaya Oblast’: former riverbed or river Irtysh near Omsk | 08.1996 | 39 |
RU-NSK-EP | Reservoir near river Nizhnyaya Eltsovka | 07.2006 | 26 | |
RU-NSK-BE | Pond in Berdsk | 06.1998 | 52 | |
Kazakhstan population | KZ-SIP-UB | Alma Ata, pond in the Botanical garden | 09.1989 | 17 |
Nearctic populations | US-ND-WA | USA, Warsing Dam | 09.05.96 | 16 |
US-ND-IS | USA, Isabel Lake | 02.1995 | 33 |
Collection sites and number of analyzed
Localities | Population abbreviation | Collection sites | Collection date | Number of specimens |
---|---|---|---|---|
Central Caucasus | CC-OS-ZM | 05.05.10 | 32 | |
Eastern Ciscaucasia | ECS-BK-ART | 26.05.17 | 47 | |
South Caucasus | SC-SJ-PA | 18.07.17 | 36 |
Consequently, the site from Republic of North-Ossetia-Alania belongs to the Central Caucasus, the site from the Republic of Dagestan belongs to the Eastern Ciscaucasia and the site from the Republic of Georgia belongs to South Caucasus or Transcaucasia. Regarding vertical zonation (
The head capsule and body of 25 larvae were slide mounted in Fora-Berlese solution. The specimens have been deposited in the Tembotov Institute of Ecology of Mountain territories RAS in Nalchik, Russia. We studied the karyotype and chromosomal polymorphism in 115 larvae from the Caucasus region.
We fixed the larvae for karyological study in ethanol-glacial acetic acid solution (3:1). The slides of the chromosomes were prepared using the ethanol-orcein technique (see Dyomin and Ilyinskaya 1988,
We performed the identification of chromosome banding sequences for arms A, E and F using the photomaps of
We studied the chromosome slides using a Carl Zeiss Axio Imager A2 microscope and performed the statistical data processing using software packages PAST 3.18 (
We used the following parameters of chromosomal polymorphism characteristics for comparison: percentage of heterozygous larvae, number of heterozygous inversions per larvae, the number of banding sequences in a population and a number of genotypic combinations per population. We calculated the genetic distances between populations according to Nei criteria (
We used the software package GenALEx 6.503 (
We performed a principal component analysis (
We measured the genetic distances (Table
We attributed the larvae of
The diploid number of chromosomes in
Karyotype of
Previously,
Heterozygous genotypic combination annA1.5. Designations as in Fig.
annA5 1a-2c 10a-12a 13ba 4a-c 2g-d 9e-4d 2h-3i 12cb 13c-16c 19d-16d 19ef C
The banding sequence annA5 was found only in the population of the South Caucasus with relatively low frequency (annA5 – 0.069) and only in the heterozygous state (annA1.5 – 0.139) (Tables
Heterozygous genotypic combination annD1.4. Designations as in Fig.
annD4 1a-3a-c 12ba 11c-a 3g-d 12dc 13a 10a 7a-4a 10e-b 13b-15e 20b-18e 17f-a 8a 18d-a 7g-b 9e-8b 16e-a 20c-24g C
The banding sequence annD4 was found only in the population of the South Caucasus with very low frequency (annD4 – 0.014) and only in the heterozygous state (annD1.4 – 0.028) (Tables
The data for European (Netherlands), Siberian, Kazakhstan and Nearctic (USA) populations are available due to
Frequency of banding sequences in different populations of
Banding sequences | European population | Caucasian populations | Siberian populations | Kazakhstan population | Nearctic populations | |||||
---|---|---|---|---|---|---|---|---|---|---|
NL-NT-NT |
ECS-BK-ART |
CC-OS-ZM |
SC-SJ- PA |
RU-OMS-IR |
RU-NSK-EP |
RU-NSK-BE |
KZ-AA-BG |
US-ND-WA |
US-ND-IS |
|
A1 | 0.438 | 0.766 | 0.313 | 0.708 | 0.910 | 0.769 | 0.865 | 0.736 | 0 | 0 |
A2 | 0.562 | 0.074 | 0.687 | 0.181 | 0.052 | 0.212 | 0.096 | 0.235 | 1 | 0.985 |
A3 | 0 | 0.160 | 0 | 0.042 | 0.038 | 0.019 | 0.039 | 0.029 | 0 | 0 |
A4 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0.015 |
A5 | 0 | 0 | 0 | 0.069 | 0 | 0 | 0 | 0 | 0 | 0 |
B1 | 0.844 | 0 | 0 | 0.778 | 0.051 | 0.173 | 0.106 | 0 | 0 | 0 |
B2 | 0.156 | 0.596 | 0 | 0 | 0.949 | 0.827 | 0.894 | 0.706 | 1 | 0.985 |
B4 | 0 | 0.404 | 1 | 0.222 | 0 | 0 | 0 | 0.234 | 0 | 0 |
B5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0.015 |
C1 | 1 | 0.394 | 0.969 | 1 | 1 | 1 | 0.981 | 0.029 | 0 | 0 |
C2 | 0 | 0.606 | 0.031 | 0 | 0 | 0 | 0.019 | 0.971 | 0 | 0 |
C3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
D1 | 1 | 0.085 | 0.156 | 0.944 | 0.538 | 0.788 | 0.673 | 0.588 | 0 | 0 |
D2 | 0 | 0.915 | 0.844 | 0.042 | 0.462 | 0.212 | 0.327 | 0.412 | 0 | 0 |
D3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
D4 | 0 | 0 | 0 | 0.014 | 0 | 0 | 0 | 0 | 0 | 0 |
E1 | 1 | 0.170 | 0.875 | 0.806 | 0.500 | 0.538 | 0.462 | 0.794 | 1 | 0.970 |
E2 | 0 | 0.830 | 0.125 | 0.194 | 0.500 | 0.462 | 0.538 | 0.206 | 0 | 0.030 |
F1 | 0.156 | 0.723 | 0.141 | 0.153 | 0.243 | 0.173 | 0.163 | 0.206 | 0 | 0 |
F2 | 0.844 | 0.277 | 0.859 | 0.847 | 0.757 | 0.827 | 0.837 | 0.794 | 0.906 | 0.742 |
F3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0.094 | 0.258 |
G1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 |
G3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
Frequency of genotypic combinations in different populations of
Genotypic combinations | European population | Caucasian populations | Siberian populations | Kazakhstan population | Nearctic populations | |||||
---|---|---|---|---|---|---|---|---|---|---|
NL-NT-NT |
ECS-BK-ART |
CC-OS-ZM |
SC-SJ- PA |
RU-OMS-IR |
RU-NSK-EP |
RU-NSK-BE |
KZ-AA-BG |
US-ND-WA |
US-ND-IS |
|
A1.1 | 0.187 | 0.574 | 0.218 | 0.500 | 0.820 | 0.654 | 0.750 | 0.529 | 0 | 0 |
A1.2 | 0.500 | 0.064 | 0.188 | 0.250 | 0.103 | 0.193 | 0.153 | 0.353 | 0 | 0 |
A2.2 | 0.313 | 0.043 | 0.594 | 0.028 | 0 | 0.115 | 0.030 | 0.059 | 1 | 0.970 |
A1.3 | 0 | 0.319 | 0 | 0.028 | 0.077 | 0.038 | 0.077 | 0.059 | 0 | 0 |
A1.5 | 0 | 0 | 0 | 0.139 | 0 | 0 | 0 | 0 | 0 | 0 |
A2.3 | 0 | 0 | 0 | 0.055 | 0 | 0 | 0 | 0 | 0 | 0 |
A2.4 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0.030 |
B1.1 | 0.687 | 0 | 0 | 0.611 | 0.103 | 0.115 | 0.038 | 0 | 0 | 0 |
B1.2 | 0.313 | 0 | 0 | 0 | 0 | 0.115 | 0.135 | 0 | 0 | 0 |
B1.4 | 0 | 0 | 0 | 0.333 | 0 | 0 | 0 | 0 | 0 | 0 |
B2.2 | 0 | 0.532 | 0 | 0 | 0.897 | 0.770 | 0.827 | 0.412 | 1 | 0.970 |
B2.4 | 0 | 0.128 | 0 | 0 | 0 | 0 | 0 | 0.588 | 0 | 0 |
B4.4 | 0 | 0.340 | 1 | 0.056 | 0 | 0 | 0 | 0 | 0 | 0 |
B2.5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0.030 |
C1.1 | 1 | 0.234 | 0.937 | 1 | 1 | 1 | 0.961 | 0 | 0 | 0 |
C1.2 | 0 | 0.319 | 0.063 | 0 | 0 | 0 | 0.039 | 0.059 | 0 | 0 |
C2.2 | 0 | 0.447 | 0 | 0 | 0 | 0 | 0 | 0.941 | 0 | 0 |
C3.3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
D1.1 | 1 | 0 | 0 | 0.889 | 0.359 | 0.616 | 0.481 | 0.353 | 0 | 0 |
D1.2 | 0 | 0.17 | 0.313 | 0.083 | 0.359 | 0.346 | 0.385 | 0.470 | 0 | 0 |
D1.4 | 0 | 0 | 0 | 0.028 | 0 | 0 | 0 | 0 | 0 | 0 |
D2.2 | 0 | 0.83 | 0.687 | 0 | 0.282 | 0.038 | 0.134 | 0.177 | 0 | 0 |
D3.3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
E1.1 | 1 | 0.043 | 0.750 | 0.639 | 0.256 | 0.308 | 0.250 | 0.706 | 1 | 0.940 |
E1.2 | 0 | 0.255 | 0.250 | 0.333 | 0.488 | 0.461 | 0.423 | 0.176 | 0 | 0.060 |
E2.2 | 0 | 0.702 | 0 | 0.028 | 0.256 | 0.231 | 0.327 | 0.118 | 0 | 0 |
F1.1 | 0 | 0.532 | 0 | 0 | 0 | 0 | 0 | 0.059 | 0 | 0 |
F1.2 | 0.313 | 0.383 | 0,281 | 0.306 | 0.487 | 0.346 | 0.327 | 0.294 | 0 | 0 |
F2.2 | 0.687 | 0.085 | 0.719 | 0.694 | 0.513 | 0.654 | 0.673 | 0.647 | 0.813 | 0.546 |
F2.3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0.187 | 0.394 |
F3.3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0.060 |
G1.1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 |
G3.3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
The level of inversion polymorphism of Caucasian
Cytogenetical characteristics of chromosomal polymorphism in different populations of
Cytogenetical characteristics | European population | Caucasian populations | Siberian populations | Kazakhstan population | Nearctic populations | |||||
---|---|---|---|---|---|---|---|---|---|---|
NL-NT-NT |
ECS-BK-ART |
CC-OS-ZM |
SC-SJ- PA |
RU-OMS-IR |
RU-NSK-EP |
RU-NSK-BE |
KZ-AA-BG |
US-ND-WA |
US-ND-IS |
|
Heterozygous larvae, % | 81 | 83 | 72 | 89 | 90 | 85 | 89 | 88 | 18 | 48 |
Average number of heterozygous inversions per larvae | 1.1 | 1.6 | 1.2 | 1.6 | 1.6 | 1.5 | 1.5 | 1.0 | 0.2 | 0.5 |
Number of banding sequences per |
10 | 14 | 12 | 15 | 13 | 13 | 14 | 14 | 8 | 11 |
Number of genotypic combinations |
11 | 19 | 13 | 19 | 15 | 17 | 18 | 18 | 8 | 12 |
On the dendrogram of genetic distances, there are four clear clusters that we conditionally assigned as European, Asian, Siberian and Nearctic clusters (Fig.
Principal component analysis (
Values of genetic distances between the different populations of
Population | NL-NT-NT | ECS-BK-ART | CC-OS-ZM | SC-SJ- PA | RU-OMS-IR | RU-NSK-EP | RU-NSK-BE | KZ-AA-BG | US-ND-WA | US-ND-IS |
---|---|---|---|---|---|---|---|---|---|---|
NL-NT-NT | 0 | |||||||||
ECS-BK-ART | 1.0628 | 0 | ||||||||
CC-OS-ZM | 0.3919 | 0.5318 | 0 | |||||||
SC-SJ-PA | 0.0724 | 0.8232 | 0.3853 | 0 | ||||||
RU-OMS-IR | 0.4069 | 0.3421 | 0.4084 | 0.2454 | 0 | |||||
RU-NSK-EP | 0.2589 | 0.4732 | 0.3952 | 0.1566 | 0.0272 | 0 | ||||
RU-NSK-BE | 0.3422 | 0.3909 | 0.409 | 0.2124 | 0.0147 | 0.0084 | 0 | |||
KZ-AA-BG | 0.5162 | 0.4259 | 0.5787 | 0.4828 | 0.4121 | 0.3845 | 0.3807 | 0 | ||
US-ND-WA | 1.1784 | 2.0094 | 1.1094 | 1.5183 | 1.2745 | 1.1585 | 1.2025 | 1.1412 | 0 | |
US-ND-IS | 1.2873 | 2.0136 | 1.2059 | 1.6637 | 1.3387 | 1.2404 | 1.2917 | 1.2424 | 0.0093 | 0 |
The principal component analysis shows almost the same picture as the dendrogram of genetic distances (Fig.
Among Caucasian populations, the frequencies of genotypic combinations in all arms of
Tree dendrogram for 10
We found the species
Overall, the Caucasian populations of the species can be characterized as relatively polymorphic. We found two new banding sequences annA5 and annD4 in the banding sequences pool of
Observed picture with Hardy-Weinberg expectation in the site from Eastern Ciscaucasia can be explained in several ways. First, it can be a negative selection of heterozygotes due to some adaptive processes that are still ongoing. Another possibility is that it is due to short time of existence of this population and founder effect.
The climate of Terek-Kuma lowland is much hotter and drier than in both other collection sites. We collected the larvae here from the puddle beside an active artesian well. This habitat is stable because it is constantly fed by water from the well. There are about 3 000 of such kind of wells (most of them still active), within the radius of ca 100 km. Most of them were drilled in the 50–60s of the 20th century for the aims of animal husbandry. Considering this, we can expect a lot of new records of this species from habitats situated beside those wells. The puddle that served as collection site is quite small (3×5m of water surface, max. depth about 0.5m) and thus the total size of the population is not so big. Possibly this population is relatively young and just over 50–60 years old. It can be presumed that initially a very small number of individuals from some nearby habitats established this population and the influx of new migrants is not so large. It is quite possible that most part of the larvae here could be relatives and so the inbreeding could occur quite often. Possibly, there was not enough time for the population to come to the equilibrium. Perhaps we see the founder effect that can also explain the observed picture with Hardy-Weinberg expectation.
All the obtained data are indicative of the complex genetic structure of Caucasian populations of