Agapanthus (Agapanthaceae) has 10 species described. However, most taxonomists differ respect to this number because the great phenotypic plasticity of the species. The cytogenetic has been an important tool to aid the plant taxon identification, and to date, all taxa of Agapanthus L'Héritier studied cytologically, presented 2n = 30. Although the species possess large chromosomes, the group is ...

BACKGROUND Failed fertilization post-ICSI has been mainly attributed to the sperm's inability to induce oocyte activation. Phospholipase C zeta (PLCζ) is considered to be one of the factors for the induction of oocyte activation. The aim of this study was to quantitatively assess the expression of PLCζ in globozoospermic men or those with previously low or failed fertilization in comparison wit...

The chromosomes of one Cichlasoma facetum and three Geophagus brasiliensis populations from the headwaters of adjacent river basins (Paraná State, southern Brazil), were investigated using differential staining techniques (C-banding, Ag-NORs, DAPI and CMA3) and fluorescent in situ hybridization (FISH) with 18S rDNA and 5S rDNA probes. The diploid chromosome number (2n) was invariably 48 in the ...

Despite being an important target of conservation concern and horticultural interest, Lebanese irises yet have a confusing taxonomic history and species' delimitation is often considered problematic, more especially among royal irises (Iris section Oncocyclus). Indeed, these irises of exceptionally large and spectacular flowers have radiated across Caucasus and eastern Mediterranean giving rise...

Morphological analysis of semen is a very important step in fertility assessment, but many semen defects are not detectable at the morphological level. These include pathological changes in sperm chromatin structure. During mammalian spermiogenesis, histone proteins associated with DNA structure are replaced by specific protamines, with which chromatin does not form nucleosomal complexes. In th...

Specimens of Arapaima gigas from Jamari River (RO) were cytogenetically analyzed. A diploid number of 2n=56 chromosomes was found (28m-sm + 28st-a). Secondary constrictions were observed on the short arms of chromosome 3. Nucleolar Organizer Regions (NORs) were detected at the subterminal region on short arms of the third chromosomal pair by both silver nitrate staining and FISH with 45S rDNA p...

The present study aimed to cytogenetically analyse five Ctenidae species Ctenus ornatus (Keyserling, 1877), Ctenus medius (Keyserling, 1891), Phoneutria nigriventer (Keyserling, 1891), Viracucha andicola (Simon, 1906), and Enoploctenus cyclothorax (Philip Bertkau, 1880), from Brazil. All species presented a 2n♂ = 28 except for V. andicola, which showed 2n♂ = 29. Analysis of segregation and beha...

Members of the family Cimicidae (Heteroptera: Cimicomorpha) are temporary bloodsuckers on birds and bats as primary hosts and humans as secondary hosts. Acanthocrios furnarii (2n=12=10+XY, male) and Psitticimex uritui (2n=31=28+X1X2Y, male) are two monotypic genera of the subfamily Haematosiphoninae, which have achiasmatic male meiosis of collochore type. Here, we examined chromatin organizatio...

The genus Phanaeus is included in the tribe Phanaeini, one of the most diverse tribes within the subfamily Scarabaeinae in terms of chromosomal characteristics. However, so far the species of this genus were not studied with differential cytogenetic techniques, limiting any inference of the probable mechanisms responsible for this diversity. In this work, several techniques were applied with th...