Comparison of the broody behavior characteristics of different breeds of geese.

A low laying performance in goose is one of the key factors preventing the industrial development, and the laying performance is related to broody behavior. However, the characteristics of broody behavior in geese remain unclear. In this study, the total 144 geese (300 day old), including Zhedong geese (Anser cygnoides), Sichuan geese (Anser cygnoides), and Carlos geese (Anser anser) were selected and assigned to 1 of 3 groups/breed (including 4♂+12♀). Laying and broody behaviors were recorded using the infrared video cameras from 2016 November 11 to 2017 June 15. The broody behavior was detected in 19.4% of Carlos geese, 33.3% of Sichuan geese, and 100% of Zhedong geese. Different goose breeds showed similar behavior characteristics. The low frequency of feeding, drinking, and low body weight were observed in the middle of broodiness. As the brooding progressed, the body temperature showed a downward trend and then recovered, whereas no difference was observed in Carlos goose. In addition, the plasma hormone concentration from different breeds and stages of broodiness were compared. The contents of FSH (follicle-stimulating hormone) and LH (luteinizing hormone) in geese were greater in the laying stage than that in the broody stage. Fewer FSH and LH were detected in Zhedong geese and Carlos geese, more in Sichuan geese. In broody goose, the PRL (prolactin) concentrations of the 3 goose breeds peaked in the middle of broodiness, and greater PRL was detected in Sichuan geese than those in Carlos geese and Zhedong geese. Finally, we compared egg production between the broody and non-broody geese in the observation period. The egg production of broody Carlos geese was 27, which was significantly higher than non-broody geese (14 eggs), while in Sichuan geese there was no significant difference between broody (24 eggs) and non-broody geese (26 eggs). Finally, the higher egg production was found with the more broody times in Zhedong geese. Taken together, although the different goose breeds showed similar broody behavior characteristics, the broody rate and hormone secretion were dissimilar, and the Zhedong geese exhibited strong broody feature.

Histological characteristics of follicles and reproductive hormone secretion during ovarian follicle development in laying geese.

Egg production in different goose breeds vary significantly, which is related with the physiology of reproduction. However, the knowledge of physiology of goose reproduction is not well documented. In the present study, the 3 breeds with significantly different egg production were selected to investigate the histological characteristics of follicles and reproductive hormone secretion during follicle development, which included Carlos geese (Anser anser), Zhejiang geese (Anser cygnoides), and Yangzhou geese (Anser cygnoides). The results indicated that there were significant differences in the morphology of ovary and follicles among different goose breeds. The mode of hierarchical follicles in Yangzhou geese was 5, and those were 3 and 4 in Zhejiang and Carlos geese, respectively. The numbers of prehierarchical follicles were 61 to 70, 69 to 75, and 28 to 39 in Yangzhou geese, Zhejiang geese, and Carlos geese, respectively. The thickness of granulosa layer of follicles was higher in the large yellow follicle than those in the other prehierarchical and hierarchical follicles, and Yangzhou geese were the highest among the 3 breeds. The concentration of follicle stimulating hormone (FSH) ranged from 12.17 to 28.06 U/L, and 17ß-Estradiol ranged from 27.01 to 49.39 pmol/L by the enzyme-linked immuno sorbent assay. The level of FSH of Yangzhou geese reached to the highest in the hierarchical follicle (F1), while the other 2 geese did not show the similar feature. In addition, the level of luteinizing hormone (LH) and progesterone (PROG) in the prehierarchical follicles of Yangzhou geese was higher than those in Carlos and Zhejiang geese. In summary, the difference of histological characteristics of follicles and reproductive hormone in different goose breeds was not only reflected in the number of follicles and the thickness of the granulose cell layer, but also embodied the secretion LH and PROG. The more thickness of the granulose cell layer and high secretions of LH and PROG contributed to the development of prehierarchical follicles to hierarchical follicles, which may be due to the fact that Yangzhou geese (Anser cygnoides) has more egg production.

Comparisons in geese of the courtship, mating behaviors and fertility of the Carlos and Sichuan breeds and the breed crosses.

The Chinese goose originated from the swan goose (Anser cygnoides) and the European goose originated from the greylag goose (Anser anser). The Chinese and European geese have the potential to crossbreed. Whether interspecific differences in mating behaviors affect successful hybridization is unknown. In this study, 10-month-old Carlos geese (n = 120; Anser anser) and Sichuan geese (Anser cygnoides) were selected, and 12 multi-male parent families (3♂+12♀) were established. The courtship and mating behaviors of pure and cross-bred combinations of the Carlos and Sichuan geese were recorded using video cameras. Initiative courtship by males was the main type of courtship. Fixed mating, mating interference, and uncooperative mating were common in the flocks. The frequencies of some courtship and mating behaviors were less in the cross-bred groups (Carlos ganders × Sichuan geese, Sichuan ganders × Carlos geese) compared with the Sichuan pure-bred groups (P < 0.05). The Carlos male geese had some unique mating behaviors (i.e., one-to-one mating, formation of distinct hierarchies, and competition interference). The fertility rate had a significant correlation with the frequency of successful mating (rp = 0.992, P < 0.05), rather than with the courtship behavior. These results indicate there were lesser frequencies of courtship and successful matings in the cross-breeding than purebreeding groups. Furthermore, the fertility rate depended largely on the successful mating behavior and was independent of the courtship behavior.

Cloning, characterization, and tissue expression pattern of mouse Nma/BAMBI during odontogenesis.

Degenerate oligonucleotides to consensus serine kinase functional domains previously identified a novel, partial rabbit tooth cDNA (Zeichner-David et al., 1992) that was used in this study to identify a full-length mouse clone. A 1390-base-pair cDNA clone was isolated encoding a putative 260-amino-acid open reading frame containing a hydrophobic 25-amino-acid potential transmembrane domain. This clone shares some homology with the TGF-beta type I receptor family, but lacks the intracellular kinase domain. DNA database analysis revealed that this clone has 86% identity to a newly isolated human gene termed non-metastatic gene A and 80% identity to a Xenopus cDNA clone termed BMP and activin membrane bound inhibitor. Here we report the mouse Nma/BAMBI cDNA sequence, the tissue expression pattern, and confirmed expression in dental cell lines. This study demonstrates that Nma/BAMBI is a highly conserved protein across species and is expressed at high levels during odontogenesis.

Human ameloblastin gene: genomic organization and mutation analysis in amelogenesis imperfecta patients.

A gene encoding the enamel protein ameloblastin (AMBN) was recently localized to a region on chromosome 4q21 containing a gene for the inherited enamel defect local hypoplastic amelogenesis imperfecta (AIH2). Ameloblastin protein is located at the Tomes processes of secretory ameloblasts and in the sheath space between rod-interrod enamel, and the AMBN gene therefore represents a viable candidate gene for local hypoplastic amelogenesis imperfecta (AI). In this study, the genomic organization of human AMBN was characterized. The gene was shown to consist of 13 exons and 12 introns. An alternatively spliced 45 bp sequence was shown not to represent a separate exon and is most likely spliced by the use of a cryptic splice site. The finding that there were no recombinations between an intragenic microsatellite and AIH2 encouraged us to evaluate this gene's potential role as a candidate gene for local hypoplastic AI. Mutation screening was performed on all 13 exons in 20 families and 8 sporadic cases with 6 different forms of AI. DNA variants were found but none that was associated exclusively with local hypoplastic AI or any of the other variants of AI in the identified Swedish families. This study excludes the coding regions and the splice sites of AMBN from a causative role in the pathogenesis of AIH2.

Enamelin maps to human chromosome 4q21 within the autosomal dominant amelogenesis imperfecta locus.

Amelogenesis imperfecta is a group of hereditary enamel defects. Of the autosomal dominant forms, only the local hypoplastic type has been mapped to human chromosome 4q 13-4q21. Enamelin is a large enamel matrix protein secreted by ameloblasts. The purpose of this study was to determine the human chromosomal localization of enamelin to establish an association with various forms of amelogenesis imperfecta. Chromosomal mapping was performed by polymerase chain reaction (PCR) amplification using somatic hybrid and deletion/derivation cell line panels with an enamelin primer set based on 100% conserved regions between pig and mouse cDNAs. Sequence-tagged site content mapping using eight markers within the critical local hypoplastic amelogenesis imperfecta region was then performed using an isolated human enamelin genomic BAC clone. The human enamelin amplicon was confirmed by DNA sequence analysis, revealing 81% and 73% identity to pig and mouse cDNAs, respectively. PCR amplification using a somatic cell hybrid panel placed enamelin on chromosome 4 with analysis of a regional chromosome 4 mapping panel refining the localization to 4q 13.1-q21.23. An identified human enamelin BAC genomic clone was shown to contain markers D4S2604 and D4S2670, as well as the first exon of the human ameloblastin gene, placing enamelin in the critical amelogenesis imperfecta locus between markers HIS1 and D4S2604 at 4q21. Our results suggest that enamelin is a strong candidate gene for this disease. Furthermore, human 4q21 may contain a second cluster of enamel matrix genes located proximally to the identified cluster of dentin and bone genes.

Cloning, characterization and immunolocalization of human ameloblastin.

Amelogenesis imperfecta is a broad classification of hereditary enamel defects, exhibiting both genetic and clinical diversity. Most amelogenesis imperfecta cases are autosomal dominant disorders, yet only the local hypoplastic form has been mapped to human chromosome 4q between D4S242 1 and the albumin gene. An enamel protein cDNA, termed ameloblastin (also known as amelin and sheathlin), has been isolated from rat, mouse and pig. Its human homolog has been mapped to chromosome 4q21 between markers D4S409 and D4S400, flanking the local hypoplastic amelogenesis imperfecta critical region. Therefore, ameloblastin is a strong candidate gene for this form of amelogenesis imperfecta. To facilitate genetic studies related to this dental disease, we isolated and characterized a human ameloblastin cDNA. A human third molar cDNA library was screened and two ameloblastin clones identified. Nucleotide sequencing of these cDNAs indicated alternative splicing of the putative open reading frame, use of different polyadenylation signals, and a high degree of similarity to reported rat, mouse and porcine cDNAs. Immunohistochemistry studies on embryonic human teeth using an antibody to recombinant ameloblastin indicated ameloblastin expression by ameloblasts with localization in the enamel matrix associated with the sheath structures.

Comparative study of MSX-2, DLX-5, and DLX-7 gene expression during early human tooth development.

Msx and Dlx family transcription factors are key elements of craniofacial development and act in specific combinations with growth factors to control the position and shape of various skeletal structures in mice. In humans, the mutations of MSX and DLX genes are associated with specific syndromes, such as tooth agenesis, craniosynostosis, and tricho-dento-osseous syndrome. To establish some relationships between those reported human syndromes, previous experimental data in mice, and the expression patterns of MSX and DLX homeogenes in the human dentition, we investigated MSX-2, DLX-5, and DLX-7 expression patterns and compared them in orofacial tissues of 7.5- to 9-wk-old human embryos by using in situ hybridization. Our data showed that MSX-2 was strongly expressed in the progenitor cells of human orofacial skeletal structures, including mandible and maxilla bones, Meckel's cartilage, and tooth germs, as shown for DLX-5. DLX-7 expression was restricted to the vestibular lamina and, later on, to the vestibular part of dental epithelium. The comparison of MSX-2, DLX-5, and DLX-7 expression patterns during the early stages of development of different human tooth types showed the existence of spatially ordered sequences of homeogene expression along the vestibular/lingual axis of dental epithelium. The expression of MSX-2 in enamel knot, as well as the coincident expression of MSX-2, DLX-5, and DLX-7 in a restricted vestibular area of dental epithelium, suggests the existence of various organizing centers involved in the control of human tooth morphogenesis.

Genetic linkage of the dentinogenesis imperfecta type III locus to chromosome 4q.

Dentinogenesis imperfecta type III (DGI-III) is an autosomal-dominant disorder of dentin formation which appears in a tri-racial southern Maryland population known as the "Brandywine isolate". This disease has suggestive evidence of linkage to the long arm of human chromosome 4 (LOD score of 2.0) in a family presenting with both juvenile periodontitis and DGI-III. The purpose of this study was to screen a family presenting with only DGI-III to determine if this locus was indeed on chromosome 4q. Furthermore, we wanted to determine if DGI-III co-localized with dentinogenesis imperfecta type II (DGI-II), which has been localized to 4q21-q23. Therefore, a large kindred from the Brandywine isolate was identified, oral examination performed, and blood samples collected from 21 family members. DNA from this family was genotyped with 6 highly polymorphic markers that span the DGI-II critical region of chromosome 4q. Analysis of the data yielded a maximum two-point LOD score of 4.87 with a marker for the dentin matrix protein 1 (DMP1) locus, a gene contained in the critical region for DGI-II. Our results demonstrated that the DGI-III locus is on human chromosome 4q21 within a 6.6 cM region that overlaps the DGI-II critical region. These results are consistent with the hypothesis that DGI-II is either an allelic variant of DGI-III or the result of mutations in two tightly linked genes.

Expression of DLX5 during human embryonic craniofacial development.

Dlx (distal-less gene) homeogenes encode transcription factors that are involved in the patterning of orofacial skeleton derived from cephalic neural crest cells. In order to study the role of DLX genes during embryonic development in human, DLX5 expression pattern was investigated in 6- to 11-week-old human embryos. A DLX5 PCR fragment was amplified from a human dental cDNA library subcloned and used for in situ hybridization investigations. DLX5 gene expression was primarily detected in the mandible at 6 weeks and then, after in the maxilla. DLX5 gene expression became restricted to progenitor cells of developing tooth germs, bones and cartilages of mandible and maxilla. During odontogenesis from bud to late cap stages, DLX5 transcripts were present in both dental epithelium and mesenchyme tissues. DLX5 expression was restricted to few cells in the vestibular aspect of the dental epithelium, while DLX5 mRNA signal was more widely distributed in dental mesenchyme. The observed expression pattern of DLX5 homeogene extends the proposed site-specific combination of homeogene expression in neural crest derived cells to human specific dentition. Furthermore, during the bud and cap stages of tooth morphogenesis, the asymmetric expression of DLX5 in the dental epithelium and dental mesenchyme may contribute to the complex patterning of human tooth shape.

Identification of a novel isoform of mouse dentin matrix protein 1: spatial expression in mineralized tissues.

Dentin matrix protein 1 (Dmp1) is an acidic phosphoprotein first identified by cDNA cloning from a rat tooth library. Northern blot hybridization of a variety of tissues detected Dmp1 mRNAs only in odontoblasts, suggesting that this protein was odontoblast specific. In situ hybridization studies showed expression of Dmp1 in odontoblasts with transient expression in secretory ameloblasts. The purpose of this study was to isolate and characterize a mouse Dmp1 cDNA and determine its spatial expression pattern related to other mineralizing tissues. A mouse molar cDNA library was screened with a 32P-labeled Dmp1 polymerase chain reaction amplification product in order to isolate a full-length clone. DNA sequence analysis of the largest mouse Dmp1 cDNA (2802 base pairs [bp]) revealed an open reading frame of 1509 nucleotides encoding a 503 amino acid protein with a single polyadenylation signal. Comparison with rat and bovine Dmp1 sequence showed high homology and the identification of a 45 bp (15 amino acid) insert, representing an alternative spliced mRNA. This 45 bp segment was shown to represent a small exon by DNA analysis of a mouse genomic Dmp1 clone. In situ hybridization studies revealed a much broader Dmp1 tissue expression pattern than previously reported. Dmp1 transcripts were detected in the odontoblast and ameloblasts, osteoblasts, and cementoblasts. Our data indicate that Dmp1 is alternatively spliced, and the primary full-length transcript contains a 45 bp insert which is encoded by a small exon. Therefore, Dmp1 is not a tooth-specific protein but rather is expressed in a number of mineralizing tissues including enamel, bone, and cementum.

Identification and characterization of a cDNA for mouse ameloblastin.

Ameloblastin was first identified as one of the most abundant novel transcripts from a random screening of a rat incisor cDNA library. In situ hybridization experiments have shown ameloblastin expression to be specific to ameloblasts, with highest levels in secretory and maturation stage ameloblasts and cells of the epithelial root sheath. Ameloblastin has been identified as a candidate gene for the local hypoplastic form of autosomal dominant amelogenesis imperfecta, by virtue of it's location within the critical disease locus. The purpose of this study was to isolate a full length mouse ameloblastin cDNA and determine its temporal expression pattern during odontogenesis. A newborn mouse molar cDNA library was screened using a rat ameloblastin cDNA probe. Positive clones were confirmed by PCR analysis with ameloblastin-specific primers, and their size determined with vector-specific primers. Phage clones were rescued to phagemid using Exassist helper phage and the nucleotide sequence determined. We report here the identification of two clones, exhibiting alternative splicing of the putative open reading frame, and use of multiple polyadenylation signals. Nucleotide sequence analysis indicated a high degree of similarity to rat ameloblastin, rat amelin 1 and 2 and porcine sheathlin. Reverse transcriptase-PCR analysis using mouse first and second mandibular molar mRNA indicated initial expression at E-14. This is one day after the initial expression of tuftelin (E-13) and one day prior to that of amelogenin (E-15).

Developmental regulation of dentin sialophosphoprotein during ameloblast differentiation: a potential enamel matrix nucleator.

The two major dentin matrix proteins, dentin sialoprotein and dentin phosphoprotein have been shown to be expressed as a single large transcript termed dentin sialophosphoprotein (DSPP). These non-collagenous matrix proteins, identified biochemically by their unique physical-chemical properties, are specific cleavage products of a large parent acidic phosphorylated protein (pI 4.0). Previous studies have shown expression of dentin sialoprotein at the protein level by ameloblasts. The purpose of this study was to determine the temporal-spatial pattern of DSPP expression during amelogenesis. In situ hybridization and immunohistochemistry were performed on sections of developing mouse molars. These data were correlated with RT-PCR analysis of in vitro enamel organ epithelium monolayer cell cultures enriched for ameloblasts. Our data indicates initial expression of the DSPP transcripts and protein during early ameloblast differentiation prior to the secretory phase when the majority of the enamel matrix is formed. Ameloblasts appear to tightly down-regulate DSPP transcription as enamel matrix formation is up-regulated. These data demonstrate DSPP expression during amelogenesis is under highly controlled developmental regulation. Therefore, DSPP may have a primary role in the initial mineralization events of both enamel and dentin, acting as a potential nucleator of hydroxyapatite crystal formation.

Dentin phosphoprotein and dentin sialoprotein are cleavage products expressed from a single transcript coded by a gene on human chromosome 4. Dentin phosphoprotein DNA sequence determination.

Dentin is the major mineralized extracellular matrix of the tooth. The organic components of dentin consist of type I collagen (90%) with 10% noncollagenous proteins, which are also components of bone. Two dentin proteins, dentin sialoprotein and dentin phosphoprotein, have been shown to be tooth-specific being expressed mostly by odontoblast cells. In this study, we screened a mouse molar tooth library for dentin sialoprotein and dentin phosphoprotein cDNA clones. Analysis of the clones resulted in characterization of a 4420-nucleotide cDNA that contained a 940-amino acid open reading frame. The signal peptide and NH2-terminal sequence was 75% homologous to the cDNA sequence of rat dentin sialoprotein. The continued open reading frame, however, contained a RGD sequence followed by a region of repeated aspartic acid and serine residues. This portion of the protein codes for amino acid sequence consistent with that of dentin phosphoprotein. The noncoding region contains three potential polyadenylation signals, two of which were shown to be utilized. Northern blot analysis indicated the presence of two major transcripts of 4.4 and 2.2 kilobases in odontoblasts. Chromosomal mapping localized the gene to human chromosome 4. These data suggest that the previously identified dentin extracellular matrix proteins, dentin sialoprotein and dentin phosphoprotein, are expressed as a single cDNA transcript coding for a protein that is specifically cleaved into two smaller polypeptides with unique physical-chemical characteristics. Therefore, we propose that the gene be named dentin sialophosphoprotein. The location of the human dentin sialophosphoprotein gene on chromosome 4 suggests that this gene may be a strong candidate gene for the genetic disease dentinogenesis imperfecta type II.

Dentin matrix protein-1, a candidate gene for dentinogenesis imperfecta.

Dentinogenesis imperfecta (DGI) is an autosomal dominant inherited dental disease which affects dentin production and mineralization. Genetic linkage studies have determined linkage between DGI type II and group-specific component (Gc, vitamin D binding protein), interferon (gamma)-induced cytokine protein 10 (INP10) and secreted phosphoprotein 1 (SSP1, osteopontin, bone sialoprotein 1, early T-lymphocyte activation 1). Therefore, the gene locus has been localized to the long arm of human chromosome 4 in the region 4q13-q21. Dentin matrix protein-1 (DMP-1, AG-1) is a new acidic, phosphorylated dentin extracellular matrix protein which has recently been identified by cDNA cloning. The purpose of this study was to establish the possible association of DMP-1 with DGI type II by determining the human chromosomal localization of this protein. A DMP-1 DNA probe was generated1using PCR amplification of the mouse full-length DMP-1 and labeled with [32P] d-CTP. A panel of rodent somatic cell hybrid clones, previously cytogenetically characterized, was used for the assignment. High stringently DNA hybridization studies and analysis of the chromosomal cell panel indicated that the DMP-1 gene locus is located on human chromosome 4. This data supports the hypothesis that DMP-1 is a candidate gene for the genetic disease DGI type II. This is based on chromosomal localization to human chromosome 4, the expression of DMP-1 mostly by odontoblasts, and its purported physical-chemical properties.