Macrochromosomes karyotypes paint your chromosomes. Medical search. Frequent questions

Avian karyotypes are characterized by internal variation in the size of chromosomes, presenting two distinct groups, macrochromosomes and microchromosomes. (pensoft.net)
Proposals based on classical cytogenetics suggested that this fact was a result of fusions of microchromosomes found in the Avian putative ancestor karyotype. (ufpa.br)

Thus, the aim of this study was to describe the karyotype structure of the Ringed Kingfisher ( Megaceryle torquata Linnaeus, 1766) and Green Kingfisher ( Chloroceryle americana Gmelin, 1788) and also compare them with related species in order to identify chromosomal rearrangements. (pensoft.net)
Thus, it is possible chromosomal fissions in macrochromosomes resulted in the increase of the diploid number, whereas chromosome fusions have originated the karyotypes with low diploid number. (pensoft.net)

The future of molecular cytogenetics is likely to depend on a better knowledge of chromosome structure and function. (biomedcentral.com)
Cyril Darlington pioneered plant cytogenetics in 1920-30 and made important advances in our understanding of mechanisms of chiasma formation and the behavior of sex chromosomes in meiosis [ 7 ]. (biomedcentral.com)
One of the purposes of this review is to encourage research into chromosome structure as this could help advance molecular cytogenetics. (biomedcentral.com)

Kingfishers comprise about 115 species of the family Alcedinidae , and are an interesting group for cytogenetic studies, for they are among birds with most heterogeneous karyotypes. (pensoft.net)
Phylogenomic studies using chromosome painting confirms the high conservation of DNA between even distantly related species [ 13 ]. (biomedcentral.com)
The highly skewed distribution of recombination events towards the chromosome ends in zebra finches and other estrildid species may function to minimize crossovers in the inverted regions. (biomedcentral.com)

We now recognize that, following DNA replication, the metaphase chromosome consists of two chromatids held together by a centromere and by cohesin. (biomedcentral.com)
In particular, a distinction between those inversions which cover both chromosome arms and thus include the centromere (pericentric inversions) and those which are restricted to a single chromosome arm (paracentric inversions) has often been made [ 9 ]. (biomedcentral.com)

Improvements in the resolution of chromosome analysis has followed closely the introduction of innovative technology. (biomedcentral.com)

Studies of karyotype structure in birds have given valuable information about evolutionary relationships. (pensoft.net)
The review provides a brief account of the structure of somatic and meiotic chromosomes, stressing the high conservation of structure in plants and animals, with emphasis on aspects that require further research. (biomedcentral.com)
These studies reaffirmed that chromosome structure and behavior in somatic and germ cell divisions were common to all plants and animals. (biomedcentral.com)
Since the genetic code was deciphered much has been learnt about the chromosome structure shared by all organisms from yeast to human. (biomedcentral.com)

They are an interesting group for cytogenetic studies since they are among birds with most heterogeneous karyotypes. (pensoft.net)
Morgan, Sturtevant, Bridges and Muller constructed the first genetic linkage maps from recombination studies in crosses made in the fruit fly and from cytological preparations of its polytene salivary gland chromosomes [ 4 - 6 ]. (biomedcentral.com)

Degrandi TM, de Oliveira JCP, de Araújo Soares A, Ledesma MA, Hass I, Garnero ADV, Gunski RJ (2018) Karyotype description and comparative analysis in Ringed Kingfisher and Green Kingfisher (Coraciiformes, Alcedinidae). (pensoft.net)

In addition, karyotype comparisons in Alcedinidae show a heterogeneity in the size and morphology of macrochromosomes, and chromosome numbers ranging from 2n = 76 to 132. (pensoft.net)

Inversions are intrachromosomal structural mutations which result in the reversal of gene order (and no change in the genic content of a chromosome) [ 4 ]. (biomedcentral.com)

According to the literature, studies performed with BAC-FISH using probes from Gallus gallus and Taeniopygia guttata (TGU) libraries have shown interactions between macro and microchromosomes and micro inversions in chromosomes previously considered conserved. (nih.gov)
Karyotypes of most bird species are characterized by around 2n = 80 chromosomes, comprising 7-10 pairs of large- and medium-sized macrochromosomes including sex chromosomes and numerous morphologically indistinguishable microchromosomes. (soken.ac.jp)
The Falconinae of the Falconiformes has a different karyotype from the typical avian karyotype in low chromosome numbers, little size difference between macrochromosomes and a smaller number of microchromosomes. (soken.ac.jp)

These karyotypic features of Falconinae were relatively different from those of Accipitridae, indicating that the drastic chromosome rearrangements occurred independently in the lineages of Accipitridae and Falconinae. (soken.ac.jp)
Growing data from non-model organisms are changing our understanding of sex chromosome evolution by challenging theoretical paradigms derived mostly from comparative karyotypic research on organisms with well-differentiated sex chromosomes, such as insects, mammals, and birds [Bachtrog et al. (karger.com)

To characterize chromosome structures of Falconinae and to delineate the chromosome rearrangements that occurred in this subfamily, we conducted comparative chromosome painting with chicken chromosomes 1-9 and Z probes and microchromosome-specific probes, and chromosome mapping of the 18S-28S rRNA genes and telomeric (TTAGGG) n sequences for common kestrel (Falco tinnunculus) (2n = 52), peregrine falcon (Falco peregrinus) (2n = 50) and merlin (Falco columbarius) (2n = 40). (soken.ac.jp)

As in EMA, comparative genome hybridization revealed putative macro XX/XY chromosomes in ESU (the 4th largest pair). (karger.com)

2012]. Current models of sex chromosome evolution propose that sex chromosomes originate from autosomes [Charlesworth and Charlesworth, 2000] and have done so multiple times independently in diverse lineages across the tree of life [Bachtrog et al. (karger.com)
2011]. Thus, the discovery of additional sex chromosome systems is critical if we are to decipher the evolution of sex-determining mechanisms and associated traits [The Tree of Sex Consortium et al. (karger.com)

2011]. Sex chromosomes are defined by the presence of a sex-determining region containing a sex-determining factor, and strong selection favors the reduction of recombination in the heterogametic sex between the sex-determining region and nearby sexually antagonistic alleles that have differential fitness effects on males versus females [Bachtrog et al. (karger.com)