Additive genetic variance and covariance between relatives in synthetic wheat crosses with variable parental ploidy levels

Cultivated bread wheat (Triticum aestivum L.) is an allohexaploid species resulting from the natural hybridization and chromosome doubling of allotetraploid durum wheat (T. turgidum) and a diploid goatgrass Aegilops tauschii Coss (Ae. tauschii). Synthetic hexaploid wheat (SHW) was developed through the interspecific hybridization of Ae. tauschii and T. turgidum, and then crossed to T. aestivum to produce synthetic hexaploid wheat derivatives (SHWDs). Owing to this founding variability, one may infer that the genetic variances of native wild populations vs improved wheat may vary due to their differential origin and evolutionary history. In this study, we partitioned the additive variance of SHW and SHWD with respect to their breed origin by fitting a hierarchical Bayesian model with heterogeneous covariance structure for breeding values to estimate variance components for each breed category, and segregation variance. Two data sets were used to test the proposed hierarchical Bayesian model, one from a multi-year multi-location field trial of SHWD and the other comprising the two species of SHW. For the SHWD, the Bayesian estimates of additive variances of grain yield from each breed category were similar for T. turgidum and Ae. tauschii, but smaller for T. aestivum. Segregation variances between Ae. tauschii—T. aestivum and T. turgidum—T. aestivum populations explained a sizable proportion of the phenotypic variance. Bayesian additive variance components and the Best Linear Unbiased Predictors (BLUPs) estimated by two well-known software programs were similar for multi-breed origin and for the sum of the breeding values by origin for both data sets. Our results support the suitability of models with heterogeneous additive genetic variances to predict breeding values in wheat crosses with variable ploidy levels.     

Genome evolution in a Mediterranean species complex: phylogeny and cytogenetics of Helictotrichon (Poaceae) allopolyploids based on nuclear DNA sequences (rDNA,topoisomerase gene) and FISH

We examined the molecular phylogeny and chromosomal features of European Helictotrichon species to explore the relationships within the genus and to investigate the origin of several polyploids. Using both approaches, molecular and cytogenetic, revealed the strong impact of allopolyploidization on genome organization from chromosome structure to sequence level. Our research focused on Mediterranean and endemic species of the Alps. Altogether, the molecular phylogenetic analyses include a sample of 17 Helictotrichon species and subspecies, used DNA sequences from the nuclear ribosomal (nr) internal transcribed spacer region (ITS) and the single copy gene topoisomerase 6 (Topo6), and were analysed by maximum parsimony and Bayesian methods. Karyotype structures were investigated by fluorescence in situ hybridization (FISH) and fluorochrome banding. Cytogenetic characters were mapped on the combined phylogenetic tree. The absence or comparatively rare occurrence of different ITS sequence types in some (allo-) polyploid species of Helictotrichon suggests frequent intergenomic homogenization of ribosomal DNA (rDNA) loci due to the phenomenon of concerted evolution. This result implies that the ITS region is not an ideal marker to study polyploid evolution of these grasses. The phylogenetic analysis of the Topo6 region revealed three major clades that concur with three different copy types (termed SAR, SET, PAR), representing the major genome groups in Helictotrichon. A comparison of the molecular phylogenetic trees with the chromosome and karyotype structure supports allopolyploidy of several Helictotrichon species and identifies potential genome donors. A correlation between molecular phylogenetic/cytogenetic results and geographic distribution is expressed by a west-east disjunction, in the narrower or wider sense, of the analysed species. While SAR represents a geographically narrowly distributed southwest Mediterranean genome group, PAR and SET are very widespread (Mediterranean to Asia) and encompass several instances of west-east disjunctions.     

Relationship between ploidy level and genome size in strawberries

This study investigated the pattern of variation in nuclear DNA content at different ploidy levels in Fragaria (Strawberry, Rosaceae) using flow cytometry based on mean fluorescent intensity (MFI) reflected by propidium-iodide-stained nuclei. On average, MFI values were 237 for diploids F. vesca, F. viridis, and F. nubicola, 416.5 for tetraploid F. orientalis, 621.5 for hexaploid F. moschata, and 798 for octoploids F. × ananassa, F. virginiana, and F. chiloensis. Within diploids MFI ranged from 225.9 in F. vesca ssp. vesca to 255.4 in F. nubicola, and within octoploids varied from 766 in F. × ananassa to 808 in F. virginiana. The nuclear DNA variation was significant among diploid species (N = 21, P < 0.008), but not across octoploid species (N = 17, P>0.386). MFI values were also variable among different genotypes of a given species though not significant. The values of mean basic genome DNA (MFI divided by ploidy level) were 118.5, 104, 103.5, and 99.8, respectively, for diploids, tetraploid, hexaploid, and octoploid species. This indicates that relative genomic size decreases by increasing ploidy level, and that there is no direct proportional relationship between DNA content and ploidy levels in Fragaria, supporting the idea of genome downsizing during polyploidization in plants.     

Variability of microsatellites BM224 and Bcal7 in populations of green toads (Bufo viridis complex) differing by nuclear DNA content and ploidy

The variability of microsatellites BM224 and Bcal7 was studied for the first time in three species of the diploid-polyploid complex of Bufo viridis (B. viridis, B. oblongus, and B. pewzowi). The locus Bcal7 was established to be monomorphic in all samples studied. In microsatellite BM224, three allele variants were found. Among tetraploid toads, the western Asiatic species B. oblongus was characterized by one allele only, the eastern B. pewzowi, by the two other alleles. A similar distribution was also revealed in triploid individuals on the borders of range between tetraploid and diploid species. Among the diploid species B. viridis samples, all three allele variants of microsatellite BM224 were observed. Their distribution in the area proved to be geographically determined. In diploid toads, a similarity was revealed between the distribution of microsatellite BM224 alleles and variability of the nuclear DNA content.     

Karyotypes and nuclear DNA amounts in Polypodium L. (Polypodiaceae)

Karyotype studies in several species of Polypodium show that telocentric chromosomes are the most common with acrocentrics forming the remainder of the complement. The relative numbers of these chromosome types can be used as indicators of species relationships although direct comparisons are difficult to make due to the large number of similar-sized chromosomes. The karyotype data support the theory that P. interjectum is a polyploid derived from the hybridization of, P. australe and P. vulgare. Measurements of nuclear DNA content show that the four diploid species P. australe, P. scouleri, P. virginianum and P. glycyrrhiza all have very similar amounts of DNA. The tetraploid P. vulgare has one-and-a-half times the DNA content of the diploids and the hexaploid P. interjectum has two times the DNA content of the diploids. The chromosomes of the tetraploid and hexaploid are smaller than those of the diploids and evolution in Polypodium appears to have been accompanied by either a loss or gain of nuclear DNA; the direction of the change cannot be ascertained by the present study.     

Correlation of protein expression, Gleason score and DNA ploidy in prostate cancer

The prognosis of prostate cancer correlates with tumor differentiation. Gleason score and DNA ploidy are two prognostic factors that correlate with prognosis. We analyzed differences in protein expression in prostate cancer of high and low aggressiveness according to these measures. From 35 prostatectomy specimens, 29 cancer samples and 10 benign samples were harvested by scraping cells from cut surfaces. DNA ploidy was assessed by image cytometry. Protein preparations from cell suspensions were examined by 2-DE. Protein spots that differed quantitatively between sample groups were identified by MS fingerprinting of tryptic fragments and MS/MS sequence analysis. We found 39 protein spots with expression levels that were raised or lowered in correlation with Gleason score and/or DNA ploidy pattern (31 overexpressed in high-malignant cancer, 8 underexpressed). Of these, 30 were identified by MS. Among overexpressed proteins were heat-shock, structural and membrane proteins and enzymes involved in gene silencing, protein synthesis/degradation, mitochondrial protein import (metaxin 2), detoxification (GST-pi) and energy metabolism. Stroma-associated proteins were generally underexpressed. The protein expression of prostate cancer correlates with tumor differentiation. Potential prognostic markers may be found among proteins that are differentially expressed and the clinical value of these should be validated.     

Homologies between nuclear and plastid DNA in spinach

Summary Homologies between spinach nuclear (n) DNA and Chloroplast (pt) DNA, have been detected with a clone bank of spinach ptDNA as hybridization probes to restriction fragments of nDNA prepared from purified root nuclei. Every cloned fragment of ptDNA showed homologies to discrete restriction fragments of nDNA, different from those of ptDNA, indicating integration of these homologies into nDNA. While most ptDNA clones were relatively large and probably contained several genes, sequence homologies were also found to the cloned plastid gene for RuBP carboxylase and the subunit of ptATPase. Many of the homologies in nDNA occur in regions of the genome that are highly methylated and are not digested by the methylation sensitive restriction endonucleases HpaII and MspI. In contrast these enzymes cleave ptDNA into small fragments which allows the nDNA homologies to be distinguished in total root DNA. The sequence homologies observed were not due to contaminating non nuclear sequences as shown by hybridization to mitochondrial (mt) and bacterial DNAs. The total amount of homology to ptDNA in nDNA is equivalent to about five copies of the plastome per haploid nuclear genome. The homologies generally appear to be in individual segments of less than 2 kbp in length, integrated into several different places in the genome.On sabbatical leave from Department of Botany, University College, Dublin, Ireland     

Reproductive development and nuclear DNA content in angiosperms

Correlates of nuclear DNA content in angiosperms have been noted previously for a range of features, cellular to geographic. A new hypothesis, the correlation between nuclear DNA content and reproductive developmental features (after Cavalier-Smith, Journal of Cell Science 34, 247–268, 1978) is posed and tested here. Of three features tested (megasporogenesis, microsporogenesis, and endosperm development), megasporogenesis alone was shown to be correlated with nuclear DNA amount. The hypothesis was examined in 107 families of angiosperms using nonparametric statistics, and in 53 families of monocotyledons and outgroups using a phylogenetic test of association. A correlation was found between large genomes and successive microsporogenesis for all angiosperms, but not for monocots and dicots analyzed separately, thus underlining the importance of taking into account phylogenetic relationships in such studies. A correlation between cellular endosperm and large genomes in dicotyledons needs to be confirmed in a phylogenetic context. A tendency for deviations from monosporic megasporogenesis to occur in taxa that have a nuclear DNA content of over 9.0 pg/C was demonstrated using both phylogenetic and nonphylogenetic tests. It is hypothesized that cytoskeleton dynamics are affected in reproductive cells, enabling decoupling between nuclear and cytoplasmic cell cycles and leading to variation in reproductive development.     

Generic relationships among the baccate-fruited Amaryllidaceae (tribe Haemantheae) inferred from plastid and nuclear non-coding DNA sequences

Using sequences from the plastid trnL-F region and nrDNA ITS, we investigated the phylogeny of the fleshy-fruited African tribe Haemantheae of the Amaryllidaceae across 19 species representing all genera of the tribe. ITS and a combined matrix produce the most resolute and well-supported tree with parsimony analysis. Two main clades are resolved, one comprising the monophyletic rhizomatous genera Clivia and Cryptostephanus, and a larger clade that unites Haemanthus and Scadoxus as sister genera to an Apodolirion/Gethyllis subclade. One of four included Gethyllis species, G. lanuginosa, resolves as sister to Apodolirion with ITS. Relationships among the Clivia species are not in agreement with a previous published phylogeny. Biogeographic analysis using the divergence/vicariance method roots the tribe in Eastern South Africa, with several subsequent dispersals to the winter rainfall Western Cape region. Chromosomal change from an ancestral 2n=22 (characteristic of Clivia) is associated with each main clade. Reduction in number has occurred in all but Cryptostephanus, which has 2n=24 chromosomes. Increasing the sampling across all of the species in the tribe will allow a more detailed understanding of the biogeographic patterns inherent in the parsimony topology, which undoubtedly reflect Quaternary climatic changes in Southern Africa.     

Embryo quality,and not chromosome nondiploidy,affects mitochondrial DNA content in mouse blastocysts

It has been shown recently that there is premature mitochondria biosynthesis in blastocysts from older women whose egg or embryo quality is poor and that aneuploid blastocysts also have a high number of mitochondrial DNA (mtDNA) copies. Whether nondiploidy/aneuploidy or reduced egg or embryo quality causes premature mitochondrial biosynthesis is not known. This study constructed haploid, diploid, triploid, and tetraploid blastocysts by parthenogenetic activation, intracytoplasmic sperm injection with one or two sperm heads, blastomere electrofusion, respectively, and generated reduced cytoplasm quality embryos from diabetic mouse and in vitro fertilization of aged oocytes, and examined whether nondiploidy or reduced cytoplasm quality causes premature mitochondrial biosynthesis. MtDNA numbers of each blastocyst from different models were tested by absolute quantitative real-time polymerase chain reaction. It was found that mtDNA content in preimplantation embryos was not associated with their chromosome ploidy, while mtDNA copy numbers in embryos with suboptimal quality were increased. Therefore, it might be the reduced cytoplasmic quality, and not chromosome nondiploidy, that causes premature mitochondria biosynthesis in blastocysts.     

Morphofunctional characterization and ploidy levels of cells in the bivalve digestive gland, with special reference to somatic polyploidy

This study investigates the histological organization and ploidy levels of the digestive gland cells in 29 species of marine, brackish water, and freshwater bivalves belonging to 5 subclasses. In all species studied, the digestive gland epithelium consists of two types of differentiated cells: digestive and basophilic. The nuclei of digestive cells contain the diploid quantity of DNA. Basophilic (secretory) cells often remain diploid also; however, in a number of species all or some of the cells showed an increase in the quantity of DNA per nucleus up to 4c. Tetraploidy of basophilic cells in several species of the subclass Anomalodesmata seems to be due to carnivory. In other species, no apparent correlation was found between selective polyploidy of basophilic cells and environmental conditions or biology traits of the bivalves. Additionally, there was no relationship between the occurrence of polyploid cells and the lifespan of the investigated species. In the bivalve mollusks, somatic polyploidy appears to be an adaptation; it is neither a tissue growth strategy nor a component of the cytodifferentiation program.     

Determination of ploidy level and nuclear DNA content in blueberry by flow cytometry

The technique of DNA flow cytometry was used to study variation in DNA content among different ploidy levels, as well as among diploid species, of Vaccinium section Cyanococcus. In a sample of plants of varying ploidy level, the relative fluorescence intensity (RFI) of nuclei stained with propidium iodide was a function of the number of chromosome sets (x), as represented by the linear equation RFI=3.7x-2.3 (r²=95%). The data indicated that DNA flow cytometry could be useful for the determination of ploidy level at the seedling stage in blueberry. They also suggest that conventional polyploid evolution has occurred in this section of the genus Vaccinium with an increase in nuclear DNA content concurrent with the increase in chromosome number. The nuclear DNA content of diploid species of Vaccinium section Cyanococcus was estimated from the relationship of the observed RFI to an internal known DNA standard (trout red blood cells). A nested analysis of variance indicated significant variation among species, as well as among populations within species, in nuclear DNA content, although this variation was small compared to the variation among ploidy levels. The variation in nuclear DNA content corresponded to the phylogenetic relationships among species determined from previous studies.     

Intraspecific DNA content variability in Festuca pallens on different geographical scales and ploidy levels

BACKGROUND AND AIMS: Intraspecific genome size variability of Festuca pallens occurring on relict rocky steppes in Central Europe was studied on two ploidy levels and three geographical scales: (1) local scale of 24 populations, (2) landscape scale of three transects in river canyons or hill systems, and (3) global scale of 160 samples covering the whole distribution area. METHODS: DAPI flow cytometry of homogeneously cultivated samples (>or=1 year), measured randomly with two internal standards, Lycopersicon esculentum and Pisum sativum. Differences in DNA content were confirmed (1) by the double peaks of simultaneously measured samples, (2) based on measurements carried out in different seasons, and (3) by additional measurements with propidium iodide. KEY RESULTS: On a global scale, the relative DNA content ranged between 1.170-fold in diploids and 1.164-fold in tetraploids. A maximum difference of 1.088-fold between the mean relative DNA content of nearby populations was found. In 16 of 24 populations significant variability was shown (P<0.001, 1.121-fold as maximum). For both ploidy levels, the relative genome size had the same range and geographical pattern, correlated with geographical coordinates (P<0.01). Diploids with larger genomes occur on relict habitats (P<0.01), and in areas of periglacial steppes (20,000 years ago; P<0.02). In tetraploids, the relative DNA content differs among the three previously recognized geographical types (Alpine, Pannonian and Scabrifolia, P<0.001). Tetraploids have a relative DNA content smaller than twice that of the diploids (P<0.001). An influence of microhabitat on DNA content variation was not confirmed. CONCLUSIONS: Genome size variability occurs over all spatial scales: intrapopulation, landscape and global. Correlation between geographical coordinates and palaeovegetation type, concomitant with diploids and tetraploids, and no influence of microhabitat were found. Genome size decreases in tetraploids. Lower CVs, and thus higher accuracy, resolution and reproducibility, favour DAPI measurements for the study of intraspecific genome size variability.     

Satellite DNA and chromosomes in Neotropical fishes: methods,applications and perspectives

Constitutive heterochromatin represents a substantial portion of the eukaryote genome, and it is mainly composed of tandemly repeated DNA sequences, such as satellite DNAs, which are also enriched by other dispersed repeated elements, including transposons. Studies on the organization, structure, composition and in situ localization of satellite DNAs have led to consistent advances in the understanding of the genome evolution of species, with a particular focus on heterochromatic domains, the diversification of heteromorphic sex chromosomes and the origin and maintenance of B chromosomes. Satellite DNAs can be chromosome specific or species specific, or they can characterize different species from a genus, family or even representatives of a given order. In some cases, the presence of these repeated elements in members of a single clade has enabled inferences of a phylogenetic nature. Genomic DNA restriction, using specific enzymes, is the most frequently used method for isolating satellite DNAs. Recent methods such as C₀t–1 DNA and chromosome microdissection, however, have proven to be efficient alternatives for the study of this class of DNA. Neotropical ichthyofauna is extremely rich and diverse enabling multiple approaches with regard to the differentiation and evolution of the genome. Genome components of some species and genera have been isolated, mapped and correlated with possible functions and structures of the chromosomes. The 5SHindIII‐DNA satellite DNA, which is specific to Hoplias malabaricus of the Erythrinidae family, has an exclusively centromeric location. The As51 satellite DNA, which is closely correlated with the genome diversification of some species from the genus Astyanax, has also been used to infer relationships between species. In the Prochilodontidae family, two repetitive DNA sequences were mapped on the chromosomes, and the SATH 1 satellite DNA is associated with the origin of heterochromatic B chromosomes in Prochilodus lineatus. Among species of the genus Characidium and the Parodontidae family, amplifications of satellite DNAs have demonstrated that these sequences are related to the differentiation of heteromorphic sex chromosomes. The possible elimination of satellite DNA units could explain the genome compaction that occurs among some species of Neotropical Tetraodontiformes. These topics are discussed in the present review, showing the importance of satellite DNA analysis in the differentiation and karyotype evolution of Actinopterygii.     

The relation between cell size, ploidy level and nitrate concentration in lettuce

In two experiments the relation between cell size, ploidy level and nitrate concentration of genotypes of lettuce ( Lactuca saliva L.) was investigated. Artificial increase of cell size by application of gibberellic acid to young plants decreased the percentage dry weight and the concentration of organic acids in the plant sap and increased the nitrate concentration of the shoot. Application of chlormequat chloride caused the opposite effects. Tetraploid genotypes of lettuce had larger cells, a lower nitrate concentration and a higher concentration of organic solutes than diploid genotypes. Genotypical differences in nitrate concentration could not be explained by differences in cell size, but were consistently related to differences in concentration of organic acids in plant sap. The percentage dry weight of genotypes was positively correlated with the concentration of organic acids in plant sap. However, differences in nitrate concentration were also found among genotypes with comparable dry matter content. These differences could be caused by differences in partitioning of photosynthates over structural components and organic acids in the vacuoles. Mono-saccharides seem to be less important than organic acids for explaining genotypical differences in nitrate level, because the concentration of monosaccharides was much lower than that of organic acids and because a negative relation between the concentration of monosaccharides and of nitrate was not found in every case. Genotypical differences in nitrate accumulation were not related to differences in osmolarity.     

Evolution of biogeographic patterns, ploidy levels, and breeding systems in a diploid-polyploid species complex of Primula

Primula sect. Aleuritia subsect. Aleuritia (Aleuritia) includes diploid, self-incompatible heterostyles and polyploid, self-compatible homostyles, the latter generally occurring at higher latitudes than the former. This study develops a phylogenetic hypothesis for Aleuritia to elucidate the interactions between Pleistocene glacial cycles, biogeographic patterns, ploidy levels and breeding systems. Sequences from five chloroplast DNA loci were analyzed with parsimony to reconstruct a phylogeny, haplotype network, and ancestral states for ploidy levels and breeding systems.The results supported the monophyly of Aleuritia and four major biogeographic lineages: an amphi-Pacific, a South American, an amphi-Atlantic and a European/North American lineage. At least four independent switches to homostyly and five to polyploidy were inferred. An Asian ancestor probably gave origin to an amphi-Pacific clade and to a lineage that diversified on the European and American continents. Switches to homostyly occurred exclusively in polyploid lineages, which mainly occupy previously glaciated areas. The higher success of the autogamous polyploid species at recolonizing habitats freed by glacial retreat might be explained in terms of selection for reproductive assurance.     

Comparison of chloroplast and mitochondrial DNA from five morphologically distinct Beta vulgaris cultivars: sugar beet,fodder beet,beet root,foliage beet,and Swiss chard

Summary Two cytoplasms, N and S, are used in the breeding of sugar beet, Beta vulgaris var. altissima. These cytoplasms can be distinguished by their mitochondrial DNA. In an attempt to detect new cytoplasms, we compared the restriction profiles of chloroplast and mitochondrial DNA from five different cultivars of Beta vulgaris. All restriction patterns of chloroplast DNA were identical. With the exception of sugar beet with S-cytoplasm, all cultivars studied showed the same restriction profile of mitochondrial DNA, indicating that these cultivars all contain the N-cytoplasm. These results are discussed with regard to the large morphological differences of the cultivars and the cytoplasmic variability found in natural populations of the wild beet, Beta maritima.     

Correlation between strand asymmetry and phylogeny in mitochondrial DNA

An evolutionary distance is introduced in order to propose an efficient and feasible procedure for phylogeny studies. Our analysis are based on the strand asymmetry property of mitochondrial DNA, but can be applied to other genomes. Comparison of our results with those reported in conventional phylogenetic trees, gives confidence about our approximation. Our findings support the hypotheses about the origin of the skew and its dependence upon evolutionary pressures, and improves previous efforts on using the strand asymmetry property of genomes for phylogeny inference. For the evolutionary distance introduced here, we observe that the more adequate technique for tree reconstructions correspond to an average link method which employs a sequential clustering algorithm.     

Genetic characterization,at the mitochondrial and nuclear DNA levels,of five Canary Island dog breeds

Many studies presenting genetic analysis of dog breeds have been conducted without the inclusion of island dog breeds, although isolation can be one of the main factors in their origin. Here we report the genetic analysis at the nuclear and mitochondrial DNA levels of five Canary Island dog breeds (Canarian Warren Hound, Canary Island Mastiff, Garafiano Shepherd, La Palma Rat‐Hunter and El Hierro Wolfhound) to fill this gap and, at the same time, genetically characterize these breeds. We identified 168 alleles in autosomal microsatellites and 16 mitochondrial haplotypes. Observed and expected heterozygosities ranged from 0.556 to 0.783 and from 0.737 to 0.943 respectively. Furthermore, three haplotypes were newly described and exclusive to a particular breed (A17+ in the Canary Island Mastiff; A33+ in the Canarian Warren Hound; Bi in the La Palma Rat‐Hunter). The outcome of our analyses also revealed different breed histories consistent with historical documents and hypothetical origin designations. Although mtDNA haplotypes showed poor breed discriminating power, autosomal markers allowed a clear clustering of each single population. We expect that our results, together with further analyses, will help to make the population histories of island dog breeds clearer.     

Relationships between bacteriospermia,DNA integrity,nuclear protamine alteration,sperm quality and ICSI outcome

The Aim of this study was to evaluate the effects of bacteriospermia on human sperm parameters, nuclear protamines, DNA integrity and ICSI outcome in patients enrolled for ICSI treatment. 84 unselected couples consulting in infertility and obstetrics clinic and enrolled for ICSI treatment were included in this study. The semen specimens were screened bacteriologically; semen and sperm parameters were also evaluated according to WHO guidelines. DNA integrity, protamines concentration and protamine deficiency were estimated by TUNEL assay, AU-PAGE and Chromomycin (CMA3) respectively. The results of this study revealed that 34.52% of studied semen samples were infected with bacteria. The isolated bacteria were identified as Staphylococcus aureus, Staph. epidermidis, Staph. haemolyticus, Escherichia coli, Enterococcus faecalis and Streptococcus agalactiae. Bacteriospermia had a significant (p?<?.010) negative effect on sperm parameters; concentration, motility, progressive motility and chromatin condensation. Moreover, high DNA fragmentation with low P1 and P2 concentrations were noticed in infected patients in comparison to non-infected patients but non-significant. Also, the fertilization rate decreased significantly (p?<?.05) with infected patients. In conclusion: bacteriospermia has significant negative effect on sperm quality and fertilization rate in patients who underwent ICSI treatment.