Cytological, histopathological and sodium dodecyl sulphate polyacrylamide gel analyses were carried out on five populations of common Nile tilapia fish (Oreochromis niloticus) occurring in five sites – River Nile (reference site), Bahr Yusef canal, Ibrahimia canal, Irrigation drain and El Moheet drain of El Minia Province, Egypt – to evaluate the usability of Nile tilapia as a biomonitor for water heavy metal contaminants. Water surface samples were collected from the five sites, and lead (Pb) concentration was shown to surpass the limits defined by WHO. Ni and Cd levels were shown to be elevated in Ibrahimia canal samples. Moreover, the concentration of heavy metals in fish muscles collected from Bahr Yusef canal and El Moheet drain was the highest in comparison with those of the other water sites. Cytological examinations of blood smears showed not only a significant percentage of micronuclei in Irrigation drain population but also a significant percentage of binucleated cells in Ibrahimia canal and El Moheet drain populations. In addition, pathological alteration was observed in blood cells, especially in samples collected from Irrigation drain and El Moheet drain. Histopathological changes were strongly observed in the liver and the kidneys of El Moheet and Irrigation drain population. Moreover, total protein band pattern profiles showed extra bands in both Ibrahimia canal and Irrigation drain more than that recorded for the River Nile population. In conclusion, cyto‐histopathological and total protein band pattern results confirmed that O. niloticus responds sensitively to the excess of heavy metals present in the water.

Garlic (Allium sativum L.) is a commonly used Allium crop worldwide. It might be expected that garlic would show some intraspecific variations because of its vegetative reproduction. The main goal of this study was to examine the chromosomal aberrations and the relationship between secondary constrictions and nucleolus organizing regions in six garlic clones. Moreover, the biochemical assessments of total protien, esterase and glutamate gxaloacetate transaminase (GOT) were also carried out. Different types of chromosomal aberrations such as (i.e.) chromosome gap, chromatid break, centromeric attenuation and end-to-end association were scored. Data showed that the highest percentage of chromosome gap (15%) was observed in EGA 2 clone. The other structural aberrations were found in different percentages. According to the presence, number and position of the secondary constrictions (SC) and satellites (SAT), four different categories for six garlic clones studied could be identified. Nucleoli number at both interphase and prophase showed consederable differences among the six clones. For instance, percentage of nucleoli at interphase varied from 94% to 97% (one nuclelus) in Sids 40 and EGA4, respectively. No cells was detected at the prophase containing four nucleoli. A strong relationship was observed between existence of the structural chromosomal aberrations and numbers and position of some cytological markers such as satellites, secondary constrictions and nucleoli. No differences were founed among all studied cloves of the six garlic clones by using total protien, esterase and GOT. In the present work, the relationship between the assessed biochemical markers and the scored chromosomal aberrations couldn't be proved.

Generally It has been accepted that the apomictic nature of nature of garlic clones could affect its cytological and genetical features as a result of accumulation of certain somatic mutations. Thus, the aim of this study is to examine some of the cytological (karyotyping, mitotic index and mitotic abnormalities) and isozyme characteristics of five garlic genotypes cultivated in Egypt (Baladi , Chinese , Chinese , 30-4 , Chinese 31-1and Chinese 31-3).Relative chromosome lengths and centromere position of these genotypes revealed insignificant difference in their karyotype formula (5 large , 2 medium from submetacentric pair and one large metacentric pair no. 5). The percentage of mitotic index of Baladi genotype (8.28%) was not very much different from that of Chinese (12.08%) whereas it was significantly lower than those of Chinese 30-4 (15.6%),Chinese 31-1(18.18%)and Chinese 31-3 (16. 8%). Means of total chromosomal abnormalities (including anuepliody, break and stickiness) were remarkably lower in genotypes Baladi (7.64%) and Chinese (9.38%)than those of Chinese 30-4 (11.94%), Chinese 31-3 (11.2%). Statistical analysis revealed that there was a high correlation (0.77) between the mitotic index and the percentage of mitotic chromosome abnormalities. Isozymes [Acid phosphatase, Glutamate Oxaloacetate Transaminase (GOT), Peroxidase and Esterase) banding patterns were qualitatively compared. The banding patterns of esterase (2bands) and GOT (one band) were similar in all five genotypes. As for Pyroxidase, the four genotypes of the Chinese origin had two bands, whereas only one band was shown by the genotype Baladi that was similar in molecular weight to small band of Chinese genotypes. All studies genotypes of acid phosphatase showed one band, which was of a low molecular weight in all except in Chinese genotype where it was a high molecular weight and Chinese 31-1 in which both low and high molecular weight bands were found.

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