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GENUS HYDROPHILUS GEOFFROY, 1762 (FIG. 6A–C, M) Material examined: Hydrophilus piceus: 2 spec. (BMNH): Greece, Corfu, R. Angus lgt. Hydrophilus pistaceus Castelnau, 1840: 1 spec. (BMNH): Spain, Caceres, Abadia, R. Angus lgt. Karyotype: 2 n = 28 + Xy p (♂). The chromosomes are short. C-banding shows all the autosomes with heavy centromeric C-bands accounting for most of their length. Comments on karyotypes: Mitosis and meiosis were studied in four species of Hydrophilus [Hydrophilus acuminatus Motschulsky, 1853, Hydrophilus indicus (Bedel, 1891), Hydrophilus piceus and Hydrophilus triangularis Say, 1823] by previous authors (Arnold, 1909; Asana et al., 1942; Smith, 1953; Agarawal, 1960a), all revealing the karyotype 2 n = 28 + Xy p (♂), which is in agreement with our findings., Published as part of Angus, Robert B, Sadílek, David, Shaarawi, Fatma, Dollimore, Hayley, Liu, Hsing-Che, Seidel, Matthias, Sýkora, Vít & Fikáček, Martin, 2021, Karyotypes of water scavenger beetles (Coleoptera: Hydrophilidae): new data and review of published records, pp. 958 in Zoological Journal of the Linnean Society 192 (3) on page 958, DOI: 10.1093/zoolinnean/zlaa105, http://zenodo.org/record/5301134, {"references":["Arnold G. 1909. The nucleolus and microchromosomes in the spermatogenesis of Hydrophilus piceus (Linn.). Archiv fur Zellforschung 2: 181 - 188.","Asana JJ, Makino S, Niiyama H. 1942. A chromosomal survey of some Indian insects IV. On the sex chromosomes of some species of beetles (Coleoptera). Cytologia 12: 187 - 205.","Smith SG. 1953. Chromosome numbers of Coleoptera. Heredity 7: 31 - 48.","Agarawal U. 1960 a. Chromosome number and sex mechanism in sixteen species of Indian Coleoptera. Current Science 29: 140."]}

GENUS NOTEROPAGUS DʼORCHYMONT, 1919 (FIG. 14A–B, G) Material examined: Noteropagus sp.: (unidentified species illustrated in Fig. 14G). 1 male (NMPC): Taiwan: Nantou County, Yushan National Park, Dongbu Scenic Area, Dong Bu 5.4 km SE of Heshe, rotten banana trunks on the margin of a village, 23.5610°N 120.93044°E, 15.v.2018, M. Fikáček, W.-R. Liang, H.-C. Liu & Y. Minoshima lgt. (2018-TW33). Karyotype: 2 n = 22. Two nuclei from testis show probably the meiotic metaphase I with 11 bivalents. The sex bivalent cannot be recognized, although the smallest element in Figure 14A appears asymmetrical. The remaining bivalents suggest that the autosomes are all more or less similar in size., Published as part of Angus, Robert B, Sadílek, David, Shaarawi, Fatma, Dollimore, Hayley, Liu, Hsing-Che, Seidel, Matthias, Sýkora, Vít & Fikáček, Martin, 2021, Karyotypes of water scavenger beetles (Coleoptera: Hydrophilidae): new data and review of published records, pp. 958 in Zoological Journal of the Linnean Society 192 (3) on page 958, DOI: 10.1093/zoolinnean/zlaa105, http://zenodo.org/record/5301134

GENUS ADOLOPUS SHARP, 1884 (FIG. 12A–C) Material examined: Adolopus sp. 1: 4 males, 3 females (NMPC): New Zealand: Stewart Island, Northwest Circuit Tk. at Kaipipi Bay, rotten longs/twigs in sparse hardwood forest with tree ferns, 46°53.88’S 168°4.31’E, 20 m a.s.l., 21.i.2016, M. Seidel & M. Fikáček lgt. (2016- NZ 017). Adolopus sp. 2: 1 male (NMPC): New Zealand, Waikato (WO), Pirongia Forest Park, Ruapane Link Track (lower part), 37.966°S 175.144°E, 235 m, 18– 21.xi.2016, M. Fikáček & M. Seidel lgt. (MM02). Karyotype: 2 n = 22 + Xy (♂). In the Kaipipi Bay species (Fig. 12B), autosome pair 1 is the longest, and remaining autosomes gradually decrease in length so that pair 11 is about a quarter of the length of pair 1. All autosomes are metacentric to submetacentric. The X chromosome is metacentric, about as long as autosome pair 5, and the Y chromosome is dotlike. Adolopus from Pirongia (Fig. 12A) differs from that of Kaipipi Bay by subacrocentric pairs 7–9 and the acrocentric X chromosome slightly longer than autosome pair 2. Note: The identification of the examined specimens is impossible at the moment; however, the DNA data (Seidel, unpubl.) indicate that they represent two different species., Published as part of Angus, Robert B, Sadílek, David, Shaarawi, Fatma, Dollimore, Hayley, Liu, Hsing-Che, Seidel, Matthias, Sýkora, Vít & Fikáček, Martin, 2021, Karyotypes of water scavenger beetles (Coleoptera: Hydrophilidae): new data and review of published records, pp. 958 in Zoological Journal of the Linnean Society 192 (3) on page 958, DOI: 10.1093/zoolinnean/zlaa105, http://zenodo.org/record/5301134

GENUS COELOSTOMA BRULLÉ, 1835 (FIG. 15A–C, H) Material examined: Coelostoma orbiculare (Fabricius, 1775): 1 male, 2 females (BMNH): United Kingdom, Norfolk, East Walton, R. Angus & F. Shaarawi lgt. Karyotype: 2 n = 26 + Xy (♂). The autosomes and the X chromosome are metacentric to submetacentric with strong centromeric C-bands. Autosome pair 6 has a distinct subterminal secondary constriction on its long arm. The Y chromosome is dot like, and there may be two small B-chromosomes in the examined specimens. All the nuclei are from eggs taken from a cocoon spun by one of the females. In total, 16 male and 6 female nuclei were photographed. The two small B-chromosomes were present in only one male nucleus., Published as part of Angus, Robert B, Sadílek, David, Shaarawi, Fatma, Dollimore, Hayley, Liu, Hsing-Che, Seidel, Matthias, Sýkora, Vít & Fikáček, Martin, 2021, Karyotypes of water scavenger beetles (Coleoptera: Hydrophilidae): new data and review of published records, pp. 958 in Zoological Journal of the Linnean Society 192 (3) on page 958, DOI: 10.1093/zoolinnean/zlaa105, http://zenodo.org/record/5301134

GENUS ANACAENA THOMSON, 1859 (FIG. 7A–D) Material examined: Anacaena gaetanae Bameul, 2001: 1 female (BMNH): France, Corsica, Corse du Sud, R. Stabiacciu, Porto Veccio, 12.vii.2009, R. B. & E.M. Angus lgt. (BMNH). Anacaena lutescens (Stephens, 1829): 3 female specs. (BMNH): Germany, Hamburg district, 16.iv.1988, R. Angus lgt.; 1 spec. (BMNH): United Kingdom, Norfolk, R. Angus lgt. Karyotype: The karyotype of A. gaetanae (Fig. 7A) is similar to that of bisexual A. lutescens (2 n = 16 + Xy p (♂)) but the chromosome taken to be the X is noticeably larger. Comments on karyotypes: The karyotypes are discussed in detail by Shaarawi & Angus (1991a). Parthenogenetic A. lutescens is heterozygous for loss of a small apical section of chromosome 8, distal to a secondary constriction (Fig. 7C). Anacaena globulus (Paykull, 1798) has a fusion of two chromosomes (autosomes) to give a reduction from eight to seven pairs (2 n = 14 + Xy p). Anacaena rufipes (Guillebeau, 1896) has two further fusions, one involving the X chromosome, to give five pairs of autosomes and neo-XY sex chromosomes (2 n = 10 + neo-XY). Shaarawi & Angus (1991a) suggested that the original small Y chromosome had also fused with the neo-Y chromosome, but it is also possible that it has simply been lost. Triploidy (3 n = 27) was found in two widely separated populations of A. lutescens, from the United Kingdom (Armathwaite, Cumbria) and the Netherlands (Doetinchem, Gelderland). In both cases diploid females were also present. In the triploids there was one pair of intact chromosome 8 and one extra chromosome 8 with the deletion. In the Armathwaite population, one of three replicates of chromosome 8 has a pericentric inversion and is acrocentric., Published as part of Angus, Robert B, Sadílek, David, Shaarawi, Fatma, Dollimore, Hayley, Liu, Hsing-Che, Seidel, Matthias, Sýkora, Vít & Fikáček, Martin, 2021, Karyotypes of water scavenger beetles (Coleoptera: Hydrophilidae): new data and review of published records, pp. 958 in Zoological Journal of the Linnean Society 192 (3) on page 958, DOI: 10.1093/zoolinnean/zlaa105, http://zenodo.org/record/5301134, {"references":["Shaarawi FAI, Angus RB. 1991 a. Chromosomal analysis of some European species of the genus Berosus Leach (Coleoptera Hydrophilidae). Koleopterologische Rundschau 61: 105 - 110."]}

GENUS STERNOLOPHUS SOLIER, 1834 (FIG. 6I–K) Material examined: Sternolophus solieri Castelnau, 1840: 1 male (BMNH): Egypt, surroundings of Cairo, 10 th Ramadan, R. Angus lgt. Karyotype: 2 n = 16 + Xy (♂). Chromosomes 1–7 metacentric, 8 subacrocentric, with an even decrease in length along the karyotype. X chromosome is metacentric, as large as chromosome 1. Note: Agarwal (1960a) provides a meioformula n = 8 + Xy p (♂) for Sternolophus rufipes (Fabricius, 1792), which agrees with the data presented here., Published as part of Angus, Robert B, Sadílek, David, Shaarawi, Fatma, Dollimore, Hayley, Liu, Hsing-Che, Seidel, Matthias, Sýkora, Vít & Fikáček, Martin, 2021, Karyotypes of water scavenger beetles (Coleoptera: Hydrophilidae): new data and review of published records, pp. 958 in Zoological Journal of the Linnean Society 192 (3) on page 958, DOI: 10.1093/zoolinnean/zlaa105, http://zenodo.org/record/5301134

GENUS OMICROGITON DʼORCHYMONT, 1919 (FIG. 14C–D, H) Material examined: Omicrogiton insularis dʼ Orchymont, 1919: 1 male, 1 female (BMNH): Taiwan, 4.8 km SEE of Tonglin, Beikeng Creek Trail, 24.04791°N 120.78434°E, 3.x.2018, rotten banana stem, M. Fikáček, H.-C. Liu, F.-S. Hu & W.-R. Liang lgt. Karyotype: 2 n = 24 + Xy (♂). Autosome pairs 1–3 and the X chromosome are metacentric and clearly larger than the other pairs. Pairs 4 and 7–12 are subacrocentric to acrocentric, and the smallest autosome is about a quarter the length of the largest. The Y chromosome is dot like., Published as part of Angus, Robert B, Sadílek, David, Shaarawi, Fatma, Dollimore, Hayley, Liu, Hsing-Che, Seidel, Matthias, Sýkora, Vít & Fikáček, Martin, 2021, Karyotypes of water scavenger beetles (Coleoptera: Hydrophilidae): new data and review of published records, pp. 958 in Zoological Journal of the Linnean Society 192 (3) on page 958, DOI: 10.1093/zoolinnean/zlaa105, http://zenodo.org/record/5301134

GENUS EXYDRUS BROUN, 1886 (FIG. 13A, D, I) Material examined: Exydrus gibbosus Broun, 1886: 1 female (NMPC): New Zealand: Wellington (WL), Tararua Range, 1 km W of Titurea Dam, start of Greens Rd., 40.4295°S 175.66064°E, 145 m, 26.xi.2016, fragment of broadleaf forest with sparse understory with ferns and Pandanus Parkinson: sifting, M. Fikáček & M. Seidel lgt. (MM31). Karyotype: 2 n = 30 (♀). The only nucleus obtained has 29 chromosomes and the karyogram shows a serious size mismatch in pair 3 so there should be at least 30 chromosomes in the karyotype, presumably 14 pairs of autosomes plus the sex chromosomes. The smallest chromosome appears heavy and almost single-stranded; however, this is almost certainly because the two chromatids of a metacentric are lying on top of each other. This is frequent with small chromosomes. There is gradual decrease in length along the karyotype, with no pair strikingly longer than the others. The smallest pair is about a third of the length of the longest pair. Most of the chromosomes are metacentric or submetacentric; however, pairs 6–9 are subacrocentric., Published as part of Angus, Robert B, Sadílek, David, Shaarawi, Fatma, Dollimore, Hayley, Liu, Hsing-Che, Seidel, Matthias, Sýkora, Vít & Fikáček, Martin, 2021, Karyotypes of water scavenger beetles (Coleoptera: Hydrophilidae): new data and review of published records, pp. 958 in Zoological Journal of the Linnean Society 192 (3) on page 958, DOI: 10.1093/zoolinnean/zlaa105, http://zenodo.org/record/5301134

GENUS LIMNOHYDROBIUS REITTER, 1909 (FIG. 5A–E) Material examined: Limnohydrobius convexus (Brullé, 1835): 2 spec. (BMNH): France, Corsica, R. Angus lgt.; 2 spec. (BMNH): Spain, Menorca, G. Foster lgt. (BMNH). Karyotype: 2 n = 16 + Xy(♂).Chromosomes1,3–5,8and X showing weak centromeric C-bands. Chromosomes 1–6 metacentric, 7, 8 and X submetacentric with X large, about as long as chromosome 5. Note: Limnohydrobius was recently separated from Hydrobius based on DNA-based phylogenetic data (Short et al., 2017); previously Limnohydrobius species were classified under the latter genus (e.g. Hansen, 1999)., Published as part of Angus, Robert B, Sadílek, David, Shaarawi, Fatma, Dollimore, Hayley, Liu, Hsing-Che, Seidel, Matthias, Sýkora, Vít & Fikáček, Martin, 2021, Karyotypes of water scavenger beetles (Coleoptera: Hydrophilidae): new data and review of published records, pp. 958 in Zoological Journal of the Linnean Society 192 (3) on page 958, DOI: 10.1093/zoolinnean/zlaa105, http://zenodo.org/record/5301134, {"references":["Short AEZ, Cole J, Toussaint EFA. 2017. Phylogeny, classification and evolution of the water scavenger beetle tribe Hydrobiusini inferred from morphology and molecules (Coleoptera: Hydrophilidae: Hydrophilinae). Systematic Entomology 42: 677 - 691.","Hansen M. 1999. World catalogue of insects. Volume 2. Hydrophiloidea (s. str.) (Coleoptera). Stenstrup: Apollo Books."]}

GENUS PARACYMUS THOMSON, 1867 (Fig. 3A–H) Material examined: Paracymus aeneus (Germar, 1824): 2 spec. (BMNH): United Kingdom, England, Isle of Wight, R. Angus lgt. Paracymus scutellaris (Rosenhauer, 1856): 2 spec. (BMNH): United Kingdom, England, Hampshire, New Forest, R. Angus lgt. Karyotype: 2 n = 16 + Xy p (♂). No C-banding was attempted. Autosome 1 is distinctly longer than the others and X is the shortest (apart from y) in both species., Published as part of Angus, Robert B, Sadílek, David, Shaarawi, Fatma, Dollimore, Hayley, Liu, Hsing-Che, Seidel, Matthias, Sýkora, Vít & Fikáček, Martin, 2021, Karyotypes of water scavenger beetles (Coleoptera: Hydrophilidae): new data and review of published records, pp. 958 in Zoological Journal of the Linnean Society 192 (3) on page 958, DOI: 10.1093/zoolinnean/zlaa105, http://zenodo.org/record/5301134

GENUS LACCOBIUS ERICHSON, 1837 (FIG. 2F–L) Material examined: Laccobius (Compsolaccobius) decorus (Gyllenhal, 1827). 2 males. (BMNH): Sweden, Öland Island, R. Angus lgt. Karyotype: 2 n = 16 + Xy p (♂). Centromeric C-bands strong. All autosomes, and X chromosome, metacentric. Autosomes similarly sized, X chromosome the largest in the nucleus. Comments on karyotypes of Laccobius: Angus & Shaarawi (1997) published the karyotype data of two species of the subgenus Laccobius [Laccobius colon (Stephens, 1829) and Laccobius minutus (Linnaeus, 1758)] and four species of the subgenus Dimorpholaccobius [Laccobius bipunctatus (Fabricius, 1775), Laccobius sinuatus Motschulsky, 1849, Laccobius striatulus (Fabricius, 1801) and Laccobius ytenensis Sharp, 1910]. Laccobius karyotypes all show 2 n = 16 + Xy p (♂). All autosomes and the X chromosome have strong centromeric C-bands, which are particularly strong in Laccobius striatulus and Laccobius sinuatus., Published as part of Angus, Robert B, Sadílek, David, Shaarawi, Fatma, Dollimore, Hayley, Liu, Hsing-Che, Seidel, Matthias, Sýkora, Vít & Fikáček, Martin, 2021, Karyotypes of water scavenger beetles (Coleoptera: Hydrophilidae): new data and review of published records, pp. 958 in Zoological Journal of the Linnean Society 192 (3) on page 958, DOI: 10.1093/zoolinnean/zlaa105, http://zenodo.org/record/5301134, {"references":["Angus RB, Shaarawi FAI. 1997. Chromosomal analysis of Chaetarthria seminulum (Herbst) and six European species of Laccobius Erichson (Coleoptera: Hydrophilidae). Koleopterologische Rundschau 67: 181 - 186."]}

Additional file 19: Table S5. Smeringopinae, summary of male cytogenetic data, including results of other authors. Doubtful data are not included. See database [24] for full list of published data on pholcid karyotypes including doubtful data. Abbreviations: a = acrocentric, bi = biarmed, CP = chromosome pair, m = metacentric, n = number of plates evaluated, p = short chromosome arm, q = long chromosome arm, SC = sex chromosome, SCS = sex chromosome system, sm = submetacentric, ® = revision of data of other authors, st = subtelocentric, t = terminal, ? = unknown, *X = data of other authors (X = reference number).

Additional file 32: Table S6. Species studied, their instar, sex, collecting data and depositories. Abbreviations: AM = Australian Museum, Sydney, Australia (specimen KS 128687), Co. = county, Hwy = highway, Isl. = island, m = male, Mts. = mountains, N = north, N.P. = national park, NW = northwest, S = south, SL = specimens lost or discarded, sm = subadult male, W = west, ZFMK = Zoological Research Museum Alexander Koenig.

Additional file 7: Table S3. Modisiminae and Ninetinae, summary of male cytogenetic data, including results of other authors. Doubtful data are not included. See database [24] for full list of published data on pholcid karyotypes, including doubtful data. Abbreviations: bi = biarmed, CP = chromosome pair, m = metacentric, n = number of plates evaluated, p = short chromosome arm, q = long chromosome arm, SC = sex chromosome, SCS = sex chromosome system, sm = submetacentric, st = subtelocentric, t = terminal, ? = unknown, *X = data of other authors (X = reference number).

Additional file 28: Appendix S1. Evolution of particular chromosomes of the pholcid X1X2Y system.

The present thesis deals with the phenomenon of additional sex chromosomes in Cimex lectularius (Hemiptera: Heteroptera: Cimicidae) using genome size analysis combined with the classical cytogenetic approach. Also, five other cimicid species and 12 species from the family Nabidae were analysed identically for comparative purposes. The thesis also pursues a description of methodical approaches of cytogenetics and flow cytometry in the study of C. lectularius. Recently analysed European specimens of C. lectularius from human host exhibited 12 distinct cytotypes, with a variable number of chromosomes X from two to 20 (2n♂ = 26+X1X2Y to 26+X1-20+Y). The fragmentation hypothesis of C. lectularius additional chromosomes X origin was established in the second half of the 20th century. However, the present genome size measurements suggest that various chromosomal rearrangements as duplication or deletion besides the fragmentation could occur. Males with basic cytotype 2n = 26+X1X2Y had average genome size of 2C = 1.94 pg, in contrast male with 2n = 26+X1-7+Y yielded 2C = 2.26 pg and also specimens with genome size decrease 2C = 1.69 pg appeared. The most informative turned up to be the relative genome size of sperm cells n = 13+X1X2 and n = 13+Y, where specimens with higher chromosome number showed...

Spiders are an intriguing model to analyse sex chromosome evolution because of their peculiar multiple X chromosome systems. Y chromosomes were considered rare in this group, arising after neo-sex chromosome formation by X chromosome-autosome rearrangements. However, recent findings suggest that Y chromosomes are more common in spiders than previously thought. Besides neo-sex chromosomes, they are also involved in the ancient X1X2Y system of haplogyne spiders, whose origin is unknown. Furthermore, spiders seem to exhibit obligatorily one or two pairs of cryptic homomorphic XY chromosomes (further cryptic sex chromosome pairs, CSCPs), which could represent the ancestral spider sex chromosomes. Here, we analyse the molecular differentiation of particular types of spider Y chromosomes in a representative set of ten species by comparative genomic hybridisation (CGH). We found a high Y chromosome differentiation in haplogyne species with X1X2Y system except for Loxosceles spp. CSCP chromosomes exhibited generally low differentiation. Possible mechanisms and factors behind the observed patterns are discussed. The presence of autosomal regions marked predominantly or exclusively with the male or female probe was also recorded. We attribute this pattern to intraspecific variability in the copy number and distribution of certain repetitive DNAs in spider genomes, pointing thus to the limits of CGH in this arachnid group. In addition, we confirmed nonrandom association of chromosomes belonging to particular CSCPs at spermatogonial mitosis and spermatocyte meiosis and their association with multiple Xs throughout meiosis. Taken together, our data suggest diverse evolutionary pathways of molecular differentiation in different types of spider Y chromosomes.

Comparative cytogenetics of the bed bug Cimex lectularius (Heteroptera: Cimicidae) The human bed bug Cimex lectularius has started enormous spreading to all developed countries of temperate climate zone during the last ten years. Bed bug was almost eradicated by a mass use of DDT in these areas until the 70's in the 20th century. This temporal haematophagous ectoparasite occupies particularly human dwellings and bat roosts. Cimex lectularius shows unusual combination of cytogenetic characteristics, general for all Heteroptera, however, not usual for other organisms. The chromosomes are holokinetic, with completely achiasmatic meiosis and inverted meiosis of the sex chromosomes. Especialy remarkable feature is intraspecific variation of the number of the X chromosomes. The variable number of chromosomes of 43 populations of Cimex lectularius from the Czech Republic and 27 populations from other European countries was studied in the present study. The 10 variants of karyotype were found out by using the "hotplate spreading" method and the standard Giemsa staining. There were male karyotypes with 2n = 29, 30, 31, 32, 33, 34, 35, 37, 42 and 47 chromosomes and two females with peculiar odd number of sex chromosomes X, 2n = 33 and 43, not complementary with any male. A stable number of 2n = 26 autosomes...

Cytogenetics of bed bugs (Cimicidae) as a model true bugs (Insecta: Heteroptera) The thesis provides current opinions about a phylogeny of bed bugs, family Cimicidae, and their classification within the order Heteroptera. There are briefly summarized cytological data about the order Heteroptera, known karyotypes of the cimicid subfamilies and introduction to cytogenetics of species Cimex lectularius Linnaeus, 1758. Heteroptera species differ from other organisms by holokinetic chromosomes, a character, in which quite frequently take place chromosomal fragmentation and fusion. Several families posses smaller pair of m chromosomes, which behave during meiosis differently from the other chromosomes. Diploid chromosomal number is extremely variable, it ranges from four (family Belostomatidae) to 80 chromosomes (family Miridae). The behavior of chromosomes in the family Cimicidae is very specific. Sex-chromosomes univalents are connected by thread-like collochores and form so-called pseudobivalents during achiasmatic post-reductional meiosis. Rare polymorphism in a number of X chromosomes occurs in Cimex lectularius populations. The diploid karyotype always consists of 26 autosomal chromosomes and at least two but up to 15 X chromosomes and one Y chromosome. The number of X chromosomes can be variable...

Spiders (Araneae) are a diverse group with various sex chromosome systems. The most common is X1X20 sex determination, X1X2 denotes two non-homologous X chromosomes and 0 the absence of Y. The presence of Y chromosome is rare among spiders and has been described mainly in Synspermiata, X1X2Y is probably ancestral constitution for this clade. The family Sicariidae was chosen to elucidate the evolution of sex chromosomes in Synspermiata. Karyotypes of 10 species whose 2n ranged from 19 to 23 were investigated in this study. The most common finding was X1X2Y in all studied Loxosceles species. The derived XY system was discovered in Sicarius. Furthermore, the distributional pattern of molecular cytogenetic markers (genes for 18S rRNA, 5S rRNA, histone H3 and U2 snRNA) was analysed using fluorescence in situ hybridization (FISH). These markers were found exclusively on autosomes, on one or two pairs. FISH with whole-genome probes of both sexes was performed to reveal distribution of Y specific sequences. Various patterns of Y differentiation were found in certain species. Y chromosome was small in all Sicariidae. A larger Y with a pronounced accumulation of Y-specific sequences has been detected in previous works - in the X1X2Y system of a synspermiate Pholcus phalongoides (Pholcidae). Pilot...

Flow cytometry is a modern technique in research, playing a significant role in biomedicine and botanics. Despite its benefits (speed, simplicity, low costs), flow cytometry is currently not used in the study of insects on a large scale. This thesis gives an overview as to how flow cytometry is used in research on insects and summarises the results of such study. This pertains to genome size and its connections to other phenomena. Other focal points of research, such as ploidy and base pair ratios, are addressed to a lesser extent. Key words: flow cytometry, use in study of insects, genome size, ploidy, invertebrates