Production and genetic characterization of interspecific hybrids among Crambe abyssinica, Crambe hispanica and Crambe kralikii.

In this paper, interspecific crosses among Crambe abyssinica, Crambe hispanica, and Crambe kralikii were reported. In the C. hispanica x C. abyssinica (H x A) cross, 118 F1 hybrids were produced without embryo rescue, while 5 F1 hybrids were obtained with embryo rescue, when C. hispanica was used as the female parent. In the reciprocal cross (A x H), 232 hybrids were obtained without embryo rescue. From more than 1000 C. kralikii flowers pollinated with pollen grains of C. abyssinica (K x A), only 2 F1 hybrids were obtained with embryo rescue, whereas the reciprocal cross produced no hybrids, even with embryo rescue. The hybrids were confirmed at the morphological, cytological, and molecular levels. In the combinations of A x H and H x A, many BC1 hybrids were obtained without embryo rescue. In contrast, in the K x A cross, only 7 BC1 plants were obtained with embryo rescue, while no seed set was achieved under self-pollination or in backcrosses without embryo rescue. In the H x A F1 hybrids, the pollen stainability was 65.4-86.0%, with an average of 76.9%. In comparison, the pollen viability of hybrids in the reciprocal cross (A x H) ranged from 66.2 to 81.1%, with an average of 75.4%. Fertile pollen grains were not found in the K x A F1 hybrids. All F1 hybrids of the 3 crosses (H x A, A x H, and K x A) had the expected 2n = 75 chromosomes. AFLP analyses indicated that all F1 hybrids and their progenies had typical bands of the parents. These hybrids and progenies are anticipated to be valuable for future C. abyssinica improvement in breeding programs.

Intra- and intergenomic chromosome pairings revealed by dual-color GISH in trigenomic hybrids of Brassica juncea and B. carinata with B. maurorum.

From dual-color genomic in situ hybridization (GISH) analysis of three trigenomic hybrids, Brassica maurorum (MM, 2n = 16) x B. juncea (AABB, 2n = 36) (M.AB), B. maurorum x B. carinata (BBCC, 2n = 34) (M.BC), and B. carinata x B. maurorum (BC.M), the three genomes of each hybrid were distinguished and autosyndesis and allosyndesis were evaluated. In M.AB, up to two autosyndetic bivalents occurred among the chromosomes of each genome; a maximum of three allosyndetic bivalents appeared between A-B, A-M, and B-M genomes. The similar pairings in M.BC and BC.M suggested that the cytoplasm of B. maurorum or B. carinata had no obvious effect on chromosome pairing. In M.BC and BC.M, a maximum of one autosyndetic bivalent was found for B and M genomes, but two were found for the C genome; from 0 to 2 allosyndetic bivalents were observed between B-C, B-M, and C-M genomes. The B-M allosyndesis frequency was higher than the A-M or C-M allosyndesis frequency in these hybrids, revealing the closer relationship of B and M genomes. The allosyndesis frequency was higher than the autosyndesis frequency among A, B, and C genomes in these combinations, suggesting that intergenomic homoeology was higher than intragenomic homoeology. The implications for genome evolution and crop breeding are discussed.

Identical sequences but different expression patterns of Hira gene in gynogenetic and gonochoristic crucian carps.

Hir/Hira (histone regulation) genes were first identified in yeast as negative regulators of histone gene expression. It has been confirmed that HIRA is a conserved family of proteins present in various animals and plants. In this paper, the cDNAs of the Hira homolog named CagHira and CaHira were isolated from gynogenetic gibel carp (gyno-carp) and gonochoristic color crucian carp (gono-carp) respectively. The full-length CagHira is 3,860 bp in length with an open reading frame (ORF) of 3,033 bp that encodes 1,011 amino acids, while the full-length CaHira is 3,748 bp in length and also has an ORF of 3,033 bp. The deduced amino acid sequences of both Hira homologs contain seven WD domains and show high identity with other HIRA family members. RT-PCR analyses revealed strong expression of Hira in the ovaries, whereas no expression was detected in the testes of either of the fishes. Hira transcription was not detected in the liver of gyno-carp, but a high level of Hira mRNA was observed in gono-carp. The temporal expression pattern showed that the Hira mRNA is consistently expressed during all embryonic development stages in gyno-carp. However, the abundance of CaHira mRNA significantly decreased (P < 0.05) shortly after fertilization and then increased again and remained stable from gastrula till hatching. The varying spatiotemporal expression patterns of Hira genes in gyno-carp and gono-carp may be associated with the differing reproductive modes used by these two closely related fishes. Our results suggest that Hira may play a role not only in the decondensation of sperm nucleus and the formation of pronucleus during fertilization, but also in gastrulation and the subsequent development of embryos.

[Influence of cleftpalate on middle ear conduction and eustachian function].

OBJECTIVE: To explore the influence and its degree of cleftpalate on middle ear conduction and eustachian function. METHOD: 41 cleftpalate patients (82 ears) were performed with otopharyngeal examinations, form of the ostium pharyngeum tubae auditivae observations and acoustic impedance measurements. The results were compared with healthy persons of normal hearing. RESULT: In the cases with cleftpalate, tympanic membrane pathological change incidence was 89.0% (73/82), ostium pharyngeum tubae auditivae of cracked shape was 59.5% (25/42), abnormal tympanogram was 83.1% (64/77), the negative rate of stapedius muscle reflex was 84.4% (65/77). There are significant different in comparison with healthy persons. In synthetic analyses, the rate of secretory otitis media with varied degree in the cleftpalate cases was 74.0% (57/77). CONCLUSION: There was a high incidence of middle ear pathological change and secretory otitis media in the cleftpalate patients. This high incidence was due to susceptivity of the nasopharynx on the infection, weak strength of the dilator tubae eustachii and the deformed shape of the ostium pharyngeum tubae auditivae.