| [polymorphism and divergence of multilocus dna markers in sibling species chironomus riparius meigen and chironomus piger strenzke (diptera, chironomidae)]. | intra- and interspecific variation and divergence of multilocus markers for genomic dna of the sibling species from the thimmi group, chironomus riparius and c. piger, were studied by pcr with arbitrary primers (rapd). a high level of rapd polymorphism was determined in both laboratory and natural populations of these species. the genetic distances were estimated between the c. riparius populations and between the sibling species c. riparius and c. piger. the genetic distance between c. riparius ... | 2003 | 14515462 |
| structure of a hemoglobin gene cluster and nucleotide sequence of three hemoglobin genes from the midge chironomus thummi piger (diptera, insecta). | the aquatic larvae of the genus chironomus (diptera, insecta) contain at least 12 different hemoglobin (hb) variants in their hemolymph. in the present study we have analysed the structure and part of the nucleotide sequence of a hb gene cluster cloned from the genomic dna of chironomus thummi piger. the cluster contains probably 6 different genes, separated by intergenic regions of various lengths. the nucleotide sequence of three putative hb genes including the intergenic regions is presented. ... | 2009 | 2775480 |
| population genetic structure and hybridization patterns in the cryptic sister species chironomus riparius and chironomus piger across differentially polluted freshwater systems. | chironomids are an integral and functionally important part of many freshwater ecosystems. yet, to date, there is limited understanding of their microevolutionary processes under chemically polluted natural environments. in this study, we investigated the genetic variation within populations of the ecotoxicological model species chironomus riparius and its cryptic sister species chironomus piger at 18 metal-contaminated and reference sites in northwestern portugal. microsatellite analysis was co ... | 2017 | 28359994 |
| characterization of heterochromatin in the salivary gland chromosomes of chironomus riparius meigen and chironomuspiger strenzke (diptera, chironomidae) by differential and fluorochrome staining. | the constitutive heterochromatin of two homosequential sibling species, chironomus riparius and chironomus piger, was studied. the salivary gland chromosomes of both species were analyzed using three staining methods: orcein and c band staining combined with dapi and cma3 fluorochrome staining. both species have the chromosome set 2n = 8, with the same banding pattern and chromosome arm combinations: ab, cd, ef, g, but they differed in number and distribution of heterochromatic bands, at-rich se ... | 2015 | 26255462 |
| [on the possibility of spontaneous interspecific hybridization in the nature of representatives of sibling-species chironomus riparius kieffer and chironomus piger strenzke (diptera, chironomidae) from armenia]. | f2 hybrid (chironomus riparius x chironomus piger) x c. piger was found in mixed community of c. riparius and c. piger. mechanism of its origin and problem of hybrid viability is considered. | 2014 | 25509157 |
| cytogenetic index and functional genome alterations in chironomus piger strenzke (diptera, chironomidae) in the assessment of sediment pollution: a case study of bulgarian and uk rivers. | the genotoxicity of trace metals in the sediments from a number of polluted sites on uk and bulgarian rivers to chironomus piger was assessed by an examination of genome instability as demonstrated by structural and functional changes to the salivary glands chromosomes. based on the metal assays, the sediments were characterized to range from 'extremely' to 'strongly contaminated'. the cytogenetic index calculated on the basis of somatic structural chromosome alterations in the polytene chromoso ... | 2015 | 25450937 |
| somatic breakpoints, distribution of repetitive dna and non-ltr retrotransposon insertion sites in the chromosomes of chironomus piger strenzke (diptera, chironomidae). | structural aberrations, their frequency and distribution as well as distribution of the tandem repetitive minisatellite dna clusters of alu and hinf elements and two retroelements, the line nlrcth1 and the sine ctrt1, were analyzed in the genome of the chironomid c. piger strenzke larvae from a bulgarian population. a consistent somatic variability in the structure of the polytene chromosomes was detected, showing that the c. piger genome is more actively rearranging than supposed before. breakp ... | 2009 | 18574700 |
| heat shock regulatory elements are present in telomeric repeats of chironomus thummi. | as in other diptera, the telomeres of chironomus thummi lack canonical short telomerase-specified repeats and instead contain complex sequences. they react to heat shock and other stress treatments by forming giant puffs at some chromosome termini, which are visible in polytene cells. all telomeres, except the telocentric end of chromosome four (4l), consist of large blocks of repeats, 176 bp in length. three subfamilies of telomeric sequences have been found to show different distribution patte ... | 2001 | 11713327 |
| the histone h1 genes of the dipteran insect, chironomus thummi, fall under two divergent classes and encode proteins with distinct intranuclear distribution and potentially different functions. | four histone h1 genes of the midge, chironomus thummi piger, and three h1 genes of the subspecies c. thummi thummi have been cloned and assigned to the four different h1 proteins from c. thummi larvae. together with an earlier cloned h1 gene from c. thummi thummi [hankeln, t. & schmidt, e. r. (1991) chromosoma 101, 25-31], these genes probably constitute the complete complement of h1 genes in both subspecies. they were found to fall under two classes that differ remarkably in their gene copy num ... | 1997 | 9432008 |
| nonreciprocal gonadal dysgenesis in hybrids of the chironomid midge chironomus thummi. iv. behavior of a female-specific protein, probably a vitellogenin. | using denaturing sds-polyacrylamide gel electrophoresis, a protein with a subunit mw of about 148,000 daltons could be detected in the fat body of females of the reciprocal hybrids of chironomus thummi thummi and chironomus thummi piger, which is not present in males. this protein is presumably a vitellogenin and can be found in both hybrids during the late fourth-instar larval stage until eclosion of the adults, i.e., in early vitellogenesis. after eclosion, the reciprocal hybrids behave differ ... | 1990 | 2085312 |
| comparison of insect hemoglobins (erythrocruorins) from chironomus thummi thummi and chironomus thummi piger (diptera). the primary structure of the monomeric hemoglobin ctp iii. | the monomeric hemoglobin fractions of chironomus thummi thummi (ctt) and chironomus thummi piger (ctp) differ in the ratio of their components. the determination of the primary structure of the component ctp iii was achieved by automatic edman degradation of the native chain, the tryptic peptides and the c-terminal fragment, obtained by cleavage at the single tryptophan residue. it revealed two chains in the ratio 1:1 which share the ambiguity threonine/isoleucine in position 57 with ctt iii. wh ... | 1989 | 2590466 |
| the nucleotide sequence and in situ localization of a gene for a dimeric haemoglobin from the midge chironomus thummi piger. | a cluster containing at least four globin genes was isolated by screening an lambda embl3 genomic dna library of the midge chironomus thummi piger (ctp) with a heterologous haemoglobin (hb) gene iv (hbiv) probe from chironomus thummi thummi (ctt). this globin gene cluster was localized by in situ hybridization to chromosome ii. one globin gene together with its 5'- and 3'-flanking regions has been sequenced. it can be deduced from the sequence that it is a new member of the dimeric hbviib family ... | 1988 | 2841201 |
| telomeric dna sequences differentially activated by heat shock in two chironomus subspecies. | the patterns of puffing, transcription and protein synthesis under heat shock were analysed in polytene nuclei of chironomus thummi piger, in comparison with those obtained in the closely related subspecies c. th. thummi. most chromosomal heat shock puffs, as well as heat shock induced polypeptides, in c. th. piger paralleled those previously reported for c. th. thummi. nevertheless, we found a striking difference in behaviour in the induction of telomeric balbiani rings by heat shock in the two ... | 1988 | 3349873 |
| the use of surface spread polytene chromosomes for high resolution fluorescence microscopic analyses. | the technique of surface spreading of polytene chromosomes is applied to fluorescence microscopy. with bisbenzimide hoechst 33258 stained surface spread polytene chromosomes from the dipteran species chironomus thummi piger, depiction of the band-interband structure is close to that of electron micrographs of the same enlargement. | 1986 | 2424149 |
| identification of a polytene chromosome band containing a male sex determiner of chironomus thummi thummi. | hybrid males of chironomus thummi piger female x ch. th. thummi male crosses were backcrossed with females of both parental stocks. fourth-instar larvae of these backcrosses showed sex specific differences in the pairing behavior of region d3d-g in chromosome arm f of salivary gland chromosome iii. analysis of the banding pattern of region d3d-g after rb and quinacrine staining demonstrated that in piger female x thummi male hybrid males a single selectively stained band occurs within this regio ... | 1985 | 3979175 |
| the nucleotide sequence of an unusual non-transcribed spacer and its ancestor in the rdna in chironomus thummi. | the nucleotide sequence of the non-transcribed spacer (nts) in the ribosomal dna (rdna) of chironomus thummi thummi and chironomus thummi piger, including major parts of the external transcribed spacer, is described. the nts of the two subspecies are very different in length, (thummi, 7 kb, piger, 2 kb); this is due to the insertion into the nts of c.th. thummi of a large cluster of highly repetitive dna sequences which are not present in the nts of c. th. piger. the repetitive sequences, called ... | 1983 | 6313353 |
| cloning and analysis of ribosomal dna of chironomus thummi piger and chironomus thummi thummi. the nontranscribed spacer of ch. th. thummi contains a highly repetitive dna sequence. | the ribosomal dnas from ch. thummi piger and ch. th. thummi were cloned and analysed by a variety of restriction endonucleases. comparison of rdna clones from the two subspecies revealed a considerable length difference: the length of the analysed rdna cistrons is approximately 9.0 kb for ch. th. piger and approximately 14.5 kb for ch. th. thummi. the nearly 5 kb additional dna in ch. th. thummi is clearly located within the non-transcribed spacer region, and consists of at-rich, repetitive dna ... | 1982 | 6301779 |
| different repetition frequencies of a 120 base-pair dna-element and its arrangement in chironomus thummi thummi and chironomus thummi piger. | the repetition frequency of a highly repetitive dna sequence has been measured in the genomes of ch. thummi thummi and ch, th, piger. this sequence is known to be involved in the evolutionary duplication of defined chromosomal segments leading to a significant increase in the genome size of ch. th. thummi. reassociation of this highly repetitive dna sequence which has a repeat length of 120 base-pairs, with total ch. th. thummi and ch. th. piger dna has shown that the repetition frequency in the ... | 1981 | 7297251 |
| [band specific differences in the labelling pattern during larval development of chironomus thummi piger]. | | 1972 | 5073284 |
| [karyotypes of chironomus thummi. i. diagram of the salivary chromosomes of chironomus thummi thummi and cytological differentiation of the subspecies chiromomus thummi thummi and chironomus thummi piger]. | | 1957 | 13523751 |