Presphenoidal synchondrosis fusion in DBA/2J mice

Cranial base growth plates are important centers of longitudinal growth in the skull and are responsible for the proper anterior placement of the face and the stimulation of normal cranial vault development. We report that the presphenoidal synchondrosis (PSS), a midline growth plate of the cranial base, closes in the DBA/2J mouse strain but not in other common inbred strains. We investigated the genetics of PSS closure in DBA/2J mice by evaluating F1, F1 backcross, and/or F1 intercross offspring from matings with C57BL/6J and DBA/1J mice, whose PSS remain open. We observed that PSS closure is genetically determined, but not inherited as a simple Mendelian trait. Employing a genome-wide SNP array, we identified a region on chromosome 11 in the C57BL/6J strain that affected the frequency of PSS closure in F1 backcross and F1 intercross offspring. The equivalent region in the DBA/1J strain did not affect PSS closure in F1 intercross offspring. We conclude that PSS closure in the DBA/2J strain is complex and modified by different loci when outcrossed with C57BL/6J and DBA/1J mice.     

Sequence-Based Analysis of the Intestinal Microbiota of Sows and Their Offspring Fed Genetically Modified Maize Expressing a Truncated Form of Bacillus thuringiensis Cry1Ab Protein (Bt Maize)

The aim was to investigate transgenerational effects of feeding genetically modified (GM) maize expressing a truncated form of Bacillus thuringiensis Cry1Ab protein (Bt maize) to sows and their offspring on maternal and offspring intestinal microbiota. Sows were assigned to either non-GM or GM maize dietary treatments during gestation and lactation. At weaning, offspring were assigned within sow treatment to non-GM or GM maize diets for 115 days, as follows: (i) non-GM maize-fed sow/non-GM maize-fed offspring (non-GM/non-GM), (ii) non-GM maize-fed sow/GM maize-fed offspring (non-GM/GM), (iii) GM maize-fed sow/non-GM maize-fed offspring (GM/non-GM), and (iv) GM maize-fed sow/GM maize-fed offspring (GM/GM). Offspring of GM maize-fed sows had higher counts of fecal total anaerobes and Enterobacteriaceae at days 70 and 100 postweaning, respectively. At day 115 postweaning, GM/non-GM offspring had lower ileal Enterobacteriaceae counts than non-GM/non-GM or GM/GM offspring and lower ileal total anaerobes than pigs on the other treatments. GM maize-fed offspring also had higher ileal total anaerobe counts than non-GM maize-fed offspring, and cecal total anaerobes were lower in non-GM/GM and GM/non-GM offspring than in those from the non-GM/non-GM treatment. The only differences observed for major bacterial phyla using 16S rRNA gene sequencing were that fecal Proteobacteria were less abundant in GM maize-fed sows prior to farrowing and in offspring at weaning, with fecal Firmicutes more abundant in offspring. While other differences occurred, they were not observed consistently in offspring, were mostly encountered for low-abundance, low-frequency bacterial taxa, and were not associated with pathology. Therefore, their biological relevance is questionable. This confirms the lack of adverse effects of GM maize on the intestinal microbiota of pigs, even following transgenerational consumption.     

Growth and development of offspring following supplementation of sow diets with oil during mid to late gestation

This study aimed to determine the consequences of altering the fatty acid profile of sow diets during mid-to-late gestation; oils of different fatty acid composition were chosen as energy supplements to provide diets with different fatty acid profiles. Forty-eight multiparous sows were used to evaluate the effects of fat supplementation from day 60 of gestation until parturition. Sows were allocated to either 3 kg/day of commercial sow pellets (control; C) or an experimental diet consisting of 3 kg/day of commercial sow pellets supplemented with 10% extra energy in the form of excess pellets (E), palm oil (P), olive oil (O), sunflower oil (S) or fish oil (F). From days 0 to 60 of gestation, all sows were given 3 kg/day of sow pellets as for the C group. The E diet resulted in the heaviest piglets at birth whereas the offspring of O and S sows were the lightest at birth. The offspring of S sows remained lighter throughout the pre-weaning period, and were also the leanest by 14 days of age. In contrast, pigs born to S sows possessed more fat by the time they reached commercial end point (≈140 days of age). In conclusion, altering the fatty acid profile of the sow diet during the second half of gestation has long-term consequences for the development of their offspring.     

Growth and development of offspring following supplementation of sow diets with oil during early to mid gestation

The role of dietary fat during early pregnancy in sows has not yet been fully established. The aim of the study was to determine the consequences of altering the fatty acid profile of sow diets during the first half of gestation; oils of different fatty acid composition were chosen as energy supplements to provide diets with different fatty acid profiles. A group of 48 multiparous sows were used to evaluate the effects of supplemental feeding during the first 60 days of gestation (term ≈ 115 days). Sows were allocated (eight per treatment) to either 3 kg/day of commercial sow pellets (control; C) or an experimental diet consisting of 3 kg/day of commercial sow pellets supplemented with 10% extra energy in the form of excess pellets (E), palm oil (P), olive oil (O), sunflower oil (S) or fish oil (F). Differential effects were observed with respect to the fatty acid profile of the diet during the first half of gestation. P sows gave birth to the largest litters. Both P and O supplementation of the maternal diet resulted in heavier piglets at birth, after correction for differences in litter size. P piglets possessed the most fat at birth and remained fatter throughout the pre-weaning period; in contrast, the offspring of O sows contained the least fat throughout life (0 to 140 days of age). The offspring of F sows exhibited improved growth performance during the neonatal period. In conclusion, altering the fatty acid profile of sow diets during the first half of gestation has long-term consequences for the growth and development of their offspring.     

Alternative farrowing systems: design criteria for farrowing systems based on the biological needs of sows and piglets

The construction of a suitable farrowing environment is a continuing dilemma: the piglet's needs must be matched with those of the sow and the farmer during the main phases that constitute farrowing: nest building, parturition and lactation. Difficulties exist in resolving the various conflicts of interest between and within these three parties (e.g. sow v. farmer: space needed for nest building v. space needed to maximise the amount of farrowing accommodation, or sow v. sow: ensuring the survival of the current litter v. maintaining condition for future litters). Thus, the challenge is to resolve these conflicts and design a system that maximises sow and piglet welfare while maintaining an economically efficient and sustainable enterprise. In order to successfully design a farrowing and lactation environment, it is necessary to consider the biological needs of both the sow and her litter. The natural behaviour of the sow has been well documented and very little variation exists between reports of peri-parturient behaviour observed in extensively kept domestic sows and their wild counterparts. The failure for domestication to significantly alter these behavioural patterns provides evidence that they are biologically significant and that the commercial farrowing environment should attempt to accommodate this behavioural repertoire. In addition, the behavioural needs of the piglets, as well as the physiological needs of both sows and their offspring should be considered. This article aims to review the considerable body of literature detailing the behavioural repertoire of sows and their offspring during the different phases of farrowing, and the accompanying physiological processes. The focus is on identifying biological needs of the animals involved in order to synthesise the appropriate design criteria for farrowing and lactation systems, which should optimise both welfare and animal production.     

Co-ordinate increase in the expression of type I and type III collagen genes in progressive systemic sclerosis fibroblasts.

Progressive systemic sclerosis (PSS), is a connective tissue disease characterized by excessive accumulation of collagen in the skin and various internal organs which is due, at least in part, to increased collagen production by PSS fibroblasts. In order to examine the molecular mechanisms responsible for this abnormality, we compared the kinetics of collagen biosynthesis, the intracellular degradation of collagen and the expression of Types I and III procollagen genes between normal and PSS dermal fibroblasts in culture. Two age- and sex-matched normal and PSS dermal fibroblast cell lines were studied. The results showed that the PSS cultures produced higher amounts of collagen than did normal fibroblasts and displayed an abnormal kinetic pattern. Furthermore, the PSS cells showed a slight but statistically significant increase in the fraction of collagen degraded intracellularly when compared with normal cells (23% against 18% respectively). The levels of mRNA for procollagen Types I and III were determined by Northern and dot-blot hybridization with specific cloned cDNA probes for alpha 1(I), alpha 2(I) and alpha 1(III) and it was found that they were 2-3-fold higher for each of the three chains in the PSS cell lines compared with the controls. These findings indicate, therefore, that the overproduction of collagen characteristic of PSS fibroblasts can be largely accounted for by the increased levels of collagen mRNA.     

Genetic variability of the tumorous-head maternal effect in Drosophila melanogaster

Summary The tumorous-head maternal effect in Drosophila melanogaster is produced by a recessive gene (tuh-1) in chromosome 1. Polymorphism exists at this locus. This maternal effect, which is part of the normal variation found in this species, is detected with the aid of a mutant gene. In the presence of the maternal effect, a semi-dominant mutant gene (tuh-3) causes homoeotic changes in the eye-antennal imaginal discs. The phenotype in the adult is known as the tumorous-head abnormality. The mutant gene, which is located in the right arm of chromosome 3, is characterized by reduced penetrance. Using the penetrance of the mutant gene as the criterion, the results of these experiments show that the level of the maternal effect activity is influenced remarkably by modifiers present in wild type strains. The assay is to mate females homozygous for tuh-1 with males homozygous for tuh-3 and to determine the percent of the offspring showing the tumorous head abnormality. Using this procedure, it was observed that parental females with various combinations of chromosomes 1 and 3 from Lausanne and Stephenville wild type strains show great variability in the level of maternal effect activity. Modifiers in chromosome 1 and 3 from the Stephenville strain increase the level of the maternal effect activity. The level is reduced if these chromosomes are replaced by those from the Lausanne strain. A major locus in chromosome 3 is in the same region occupied by clusters of functionally related genes with regulating action. These results demonstrate that the penetrance of a mutant gene, which acts during embryogenesis, is influenced by modifiers which act during oogenesis.This investigation was supported by Public Health Service Research Grant GM 18664 to Arizona State University from the National Institute of General Medical Sciences     

Fertility effects of chromosome rearrangement (insertion 16) in Charolais cattle from Brazil

Insertion 16, a structural chromosome abnormality originated by three breaks in one autosome, was detected with familial recurrence in a Charolais cattle population. Due to the peculiar nature of Insertion 16, its effect on the fertility of the carriers was verified by various parameters. A total of 115 animals was karyotyped to learn the segregational behavior of the chromosome abnormality, and 1,354 females were studied to evaluate the reproductive efficiency of the propositi, a pair of chimeric bulls for insertion 16. Their fertility was observed and compared with that of three normal bulls. Analysis of the results revealed that insertion 15 segregates in the offspring of only one heterozygous proposita, without sex preference, and that the percentage of conceptions in the cows inseminated by the propositi was similar to the controls'; however, for each conception with the semen of the propositus in which the insertion segregated, 0.16 more inseminations were necessary than for the controls. Similarly, the deviation in the percentage of nonreturns after the first insemination (15.9%) and the frequency of abnormal oestrous cycles (10.3%) indicate reduced fertility in the propositus, which is related to early embryo mortality.     

Structural differences in reciprocal translocations

Summary Interchange segment sizes and the sizes of chromosome imbalance arising from the different modes of meiotic segregation were measured in a selected sample of 20 reciprocal translocations (Rcp). The Rcp were selected by two modes of ascertainment: (I) neonates with an unbalanced form of the translocation, and (II) couples with recurrent spontaneous abortions without evidence of full-term translocation aneuploid offspring.The measurements (% of haploid autosomal length: %HAL) were plotted as the observed or potential chromosomal imbalance with monosomy (abscissa) and trisomy (ordinate). It was found that (a) the interchange segments were larger in the spontaneous abortion Rcp, (b) that all of the imbalances observed in full-term neonates plotted close to the origin and to the left of the line joining 4% trisomy to 2% monosomy, and (c) the imbalances observed in the neonates in each individual Rcp were of the smallest size possible arising by any segregation mode.It was concluded that a major factor in the survival to term of aneuploid conceptuses is the size (proportion of genome) of the chromosome abnormality, irrespective of the origin of the chromosome regions. These results are discussed in relation to their use as a model to evaluate the risk of abnormal offspring in the progeny of translocation heterozygotes (the Chromosome Imbalance Size-Viability Model).     

A whole genome scan to detect quantitative trait loci for gestation length and sow maternal ability related traits in a White Duroc × Erhualian F2 resource population

Gestation length and maternal ability are important to improve the sow reproduction efficiency and their offspring survival. To map quantitative trait loci (QTL) for gestation length and maternal ability related traits including piglet survival rate and average body weight of piglets at weaning, more than 200 F2 sows from a White Duroc × Erhualian resource population were phenotyped. A genome-wide scan was performed with 194 microsatellite markers covering the whole pig genome. QTL analysis was carried out using a composite regression interval mapping method via QTL express. The results showed that total number of born piglets was significantly correlated with gestation length (r = -0.13, P < 0.05). Three QTL were detected on pig chromosome (SSC)2, 8 and 12 for gestation length. The QTL on SSC2 achieved the 5% genome-wide significant level and the QTL on SSC8 was consistent with previous reports. Four suggestive QTL were identified for maternal ability related traits including 1 QTL for survival rate of piglets at weaning on SSC8, 3 QTL for average body weight of piglet at weaning on SSC3, 11 and 13.     

Chromosomal abnormalities among offspring of childhood-cancer survivors in Denmark: a population-based study

Ionizing radiation and many cancer drugs have the potential to produce germ-cell mutations that might lead to genetic disease in the next generation. In a population-based study, we identified, from records in the Danish Cancer Registry, 4,676 children treated for cancer. Their 6,441 siblings provided a comparison cohort. The results of a search of the Central Population Register identified 2,630 live-born offspring of the survivors and 5,504 live-born offspring of their siblings. The occurrence of abnormal karyotypes diagnosed in these offspring and also in any pregnancies terminated following prenatal diagnosis of a chromosome abnormality was determined from the Danish Cytogenetic Registry. After exclusion of hereditary cases and inclusion of the prenatal cases, after correction for expected viability, the adjusted proportion of live-born children in survivor families with abnormal karyotypes (5.5/2,631.5 [0.21%]) was the same as that among the comparison sibling families (11.8/5,505.8 [0.21%]). There were no significant differences in the occurrence of Down syndrome (relative risk [RR]=1.07; 95% CI 0.16-5.47) or Turner syndrome (RR=1.32; 95% CI 0.17-7.96) among the children of cancer survivors, compared with the children of their siblings. These reassuring results are of importance to the survivors, to their families, and to genetic counselors.     

Persistence of antibiotic resistance: evaluation of a probiotic approach using antibiotic-sensitive Megasphaera elsdenii strains to prevent colonization of swine by antibiotic-resistant strains

Megasphaera elsdenii is a lactate-fermenting, obligately anaerobic bacterium commonly present in the gastrointestinal tracts of mammals, including humans. Swine M. elsdenii strains were previously shown to have high levels of tetracycline resistance (MIC=64 to >256 μg/ml) and to carry mosaic (recombinant) tetracycline resistance genes. Baby pigs inherit intestinal microbiota from the mother sow. In these investigations we addressed two questions. When do M. elsdenii strains from the sow colonize baby pigs? Can five antibiotic-sensitive M. elsdenii strains administered intragastrically to newborn pigs affect natural colonization of the piglets by antibiotic-resistant (AR) M. elsdenii strains from the mother? M. elsdenii natural colonization of newborn pigs was undetectable (<10⁴ CFU/g [wet weight] of feces) prior to weaning (20 days after birth). After weaning, all pigs became colonized (4 × 10⁵ to 2 × 10⁸ CFU/g feces). In a separate study, 61% (76/125) of M. elsdenii isolates from a gravid sow never exposed to antibiotics were resistant to chlortetracycline, ampicillin, or tylosin. The inoculation of the sow''s offspring with mixtures of M. elsdenii antibiotic-sensitive strains prevented colonization of the offspring by maternal AR strains until at least 11 days postweaning. At 25 and 53 days postweaning, however, AR strains predominated. Antibiotic susceptibility phenotypes and single nucleotide polymorphism (SNP)-based identities of M. elsdenii isolated from sow and offspring were unexpectedly diverse. These results suggest that dosing newborn piglets with M. elsdenii antibiotic-sensitive strains delays but does not prevent colonization by maternal resistant strains. M. elsdenii subspecies diversity offers an explanation for the persistence of resistant strains in the absence of antibiotic selection.     

Male-offspring-specific, haplotype-dependent, nonrandom cosegregation of alleles at loci on two mouse chromosomes

F(1) backcrosses involving the DDK and C57BL/6 inbred mouse strains show transmission ratio distortion at loci on two different chromosomes, 11 and X. Transmission ratio distortion on chromosome X is restricted to female offspring while that on chromosome 11 is present in offspring of both sexes. In this article we investigate whether the inheritance of alleles at loci on one chromosome is independent of inheritance of alleles on the other. A strong nonrandom association between the inheritance of alleles at loci on both chromosomes is found among male offspring, while independent assortment occurs among female offspring. We also provide evidence that the mechanism by which this phenomenon occurs involves preferential cosegregation of nonparental chromatids of both chromosomes at the second meiotic division, after the ova has been fertilized by a C57BL/6 sperm bearing a Y chromosome. These observations confirm the influence of the sperm in the segregation of chromatids during female meiosis, and indicate that a locus or loci on the Y chromosome are involved in this instance of meiotic drive.     

Congenitally caused fused labia in the common marmoset (Callithrix jacchus)

In this paper, the occurrence of an external genital abnormality in female marmoset monkeys (fused labia) is discussed. This malformation was detected, for the first time, in a group of animals at the German Primate Center (GPC), Goettingen. The malformed vulva was completely sealed except for an opening of 1.5-2.5 mm around the urethra sufficient for urination. Because of this defect the animals were not able to copulate. As a consequence, the affected females were functionally infertile although they had a normal genital tract and a regular cycle. This vulvar abnormality was found in 12 females, offspring of 10 pairs in which either one or both came to the German Primate Center from two genetically related colonies in Munich, Germany, and one colony in Basel, Switzerland. The abnormality appeared to be recessive and inheritable from either parent. In pairs in which both animals were from one of the mentioned colonies, 45% of the female offspring were affected. In pairs where only one partner came from these colonies, 26% of female offspring had the malformation. These results indicate that avoidance of inbreeding, which is frequently performed in primate colonies, may reduce, but not eliminate the expression of abnormalities of genetic origin. Therefore selective breeding is required, and, in colonies where these recessive mutations are widespread, the development of genetic screening tests would be advantageous.     

Hyperthermia of male Drosophila melanogaster meiocytes induces abnormalities in both paternal and maternal sex chromosome sets of the offspring

Nondisjunction and loss of sex chromosomes caused by exposure of male Drosophila melanogaster to heat shock (HS) (37 degrees C for 1 h) has been studied to determine the role of mutation l(1)ts403 (sbr10) in the control of chromosome segregation during cell division. Hyperthermia of males at the pupal stage has been demonstrated to increase the number of offspring with abnormalities of not only paternal, but also maternal sex chromosome sets. According to the criterion used, there is a temperature-sensitive period of spermatogenesis, which presumably coincides with meiosis. Phenotypes of some individuals correspond to the presence of two sex chromosomes of obtained from the same parent. The frequency of abnormal chromosome sets in the offspring of male carriers of the sbr10 mutation is about two times higher than in the offspring of males without this mutation.     

An XXY mouse, the result of a rearrangement between one X and a Y chromosome

A male mouse with irregular white spotting, typical of piebald, s, arose during an experiment designed to search for mutations induced in spermatogonial cells by ethylnitrosourea (ENU). On being examined cytologically it was found to carry 40 chromosomes but was effectively XXY since one of the two X chromosomes present was distally fused to a Y chromosome. In common with the previously described XXY mice, all of which carried 41 chromosomes, the mouse was sterile with a total absence of germ cells. Because of this, it was not possible to determine if the white spotting was inherited. The spotting could not be related to any observable abnormality of chromosomes known to carry spotting genes, nor could it be linked in any way with the X and Y fusion. It was concluded from the cytological considerations and the time interval (6 months) that had elapsed between mutagen treatment and birth of the offspring, that whereas the spotting was probably the result of ENU damage in a spermatogonial stem cell, the XY fusion was probably a later and spontaneous event.     

Interaction of CP levels in maternal and nursery diets,and its effect on performance,protein digestibility,and serum urea levels in piglets

Reduced protein levels in nursery diets have been associated with a lower risk of postweaning diarrhea, but the interaction with CP levels in maternal diet on the performance of the offspring remains unclear. The objective of this study was to determine the effect of protein content in sow gestation and piglet nursery diets on the performance of the piglets until slaughter. This was studied in a 2 × 2 factorial trial (35 sows, 209 piglets), with higher or lower (H or L) dietary CP in sow diets (168 vs 122 g CP/kg) during late gestation. A standard lactation feed was provided for all sows (160 g CP/kg). For both sow treatments, half of the litters received a higher or lower CP in the piglet nursery diet (210 vs 166 g CP/kg). This resulted in four possible treatment combinations: HH, HL, LH and LL, with sow treatment as first and piglet treatment as second letter. For each phase, all diets were iso-energetic and had a similar level of essential amino acids. P_s*p is the p-value for the interaction effect between sow and piglet treatment. In the nursery phase (3.5–9 weeks of age), a tendency toward interaction between piglet and sow treatments with feed efficiency (P_s*p = 0.08) was observed with HH having the highest gain:feed ratio (G:F) (0.74 ± 0.01), LH the lowest (0.70 ± 0.01) and the other two groups intermediate. In the growing-finishing phase, an interaction was observed between the piglet and sow diets with decreased G:F for LH (P_s*p = 0.04) and a tendency toward interaction with increased daily feed intake for LH (P_s*p = 0.07). The sow diet showed a tendency toward a long-lasting effect on the dressing percentage and meat thickness of the offspring, which was higher for the progeny of H sows (P_s < 0.01 and P_s = 0.02, respectively). At 23 weeks, serum urea concentrations tended to be lower for the HH and LL groups (P_s*p = 0.07). Fecal consistency scores were higher at day 10–day 14 after weaning for piglets from L sows (P_s = 0.03 and P_s < 0.01, respectively). At day 7 after weaning, fecal consistency score was higher for piglets fed the higher protein diet (P_p < 0.01). At 8 weeks of age, the apparent total tract digestibility of CP (ATTD_CP) interacted between piglet and sow diet (P_s*p = 0.02), with HH showing the highest digestibility values. In conclusion, the protein levels in sow late-gestation and piglet nursery diets interacted with feed efficiency, ATTD_CP and serum urea concentrations in the nursery phase.     

A cytogenetic investigation of the effects of cryopreservation on human sperm.

The effects of cryopreservation on the frequency and type of chromosome abnormalities in human sperm have been investigated for the first time. With a technique which enables direct visualization of human sperm chromosomes following in vitro penetration of hamster oocytes, sperm samples from 13 normal men were examined before and after being frozen in liquid nitrogen. The overall abnormality frequencies of 17.8% for fresh semen and 13.4% for previously frozen semen were not significantly different (chi 2(1) df = 3.04, p = 0.08). When specific abnormality types were analyzed, only the category of hypohaploidy was significantly different (chi 2(1) df = 6.75, p = 0.009) before (7.5%) and after (3.4%) freezing. Hypohaploidy was significantly higher than hyperhaploidy both prefreeze and postfreeze, and chromosome loss was random. Because the observed excess of hypohaploid cells may be attributable to technical artifact, the aneuploidy levels were estimated by doubling the number of hyperhaploid cells. Neither the adjusted numerical abnormality frequencies (1% prefreeze vs. 0% postfreeze) nor the overall abnormality frequencies (11.8% prefreeze vs. 10.4% postfreeze) were significantly different. The types and distributions of karyotypically abnormal sperm complements (numerical, structural, or combined) observed before and after freezing were not different. Interdonor variability in sperm chromosome abnormality frequencies and a possible donor-dependent response to cryopreservation were suggested by the data. The sex ratios were not affected by cryopreservation and did not differ significantly from the theoretical 50%. It is concluded that cryopreservation does not affect the type or frequencies of chromosome abnormalities or alter the sex ratio in human sperm.     

应用染色体涂染技术分析两例染色体结构异常 Analysis of the Structure of Abnormal Karyotypes by Using Chromosome Painting

为了确定两例细胞遗传学提示染色体结构异常的核型,应用通过显微切割技 术构建的人类18号和7号染色体探针池,分别对这两例病例的中期分裂相进行染色体涂染,结合显带染色体,确定两者核型分别为46,XY,t(3;18) (q12;q21)和46,XX,dir ins(1;7)(p3104;q34q36)。染色体涂染技术是染色体显带技术的重要补充和发展,为染色体结构异常提供了一种直观、准确的检测手段,在遗传咨询和产前诊断方面有重要作用。 Abstract:In this study,chromosome painting technique was performed to analyse the abnormal karyotypes of two carriers.Chromosome 18 and 7 specific libraries,which were generated by chromosome microdissection technique,were used as probe pools to hybridize the carriers metaphase chromosomes respectively.Unlabled human genomic DNA was used to inhibit the hybridization of sequences in the library that bind to mutiple chromosomes.Structure abnormality was detected clearly in metaphase.Combined with the banding chromosomes,we concluded that their karytypes were 46,XY,t(3;18)(q12;q21)and 46,XX,dir ins(1;7)(p3104;q34q36).Chromosome painting,as a direct and concise method in analysing chromosome structure abnormality,is an important complement and development of chromosome banding technique,and has important application in genetic counselling and prenatal diagnosis.