Tetraploid rye was crossed with different tetraploid triticale lines. The F1 generation of tetraploid rye x tetraploid triticale hybrids was backcrossed with 4x rye. After backcrossing, all BC1 F1 plants were subjected to open pollination, whereas in the BC1 F2 generations only plants with wheat chromosomes in their karyotypes were open pollinated. Substitution, addition and addition substitution lines of wheat chromosomes in tetraploid rye were isolated from the F2 and F3 of BC1 . In 60 plants of BC1 F2 , 59 chromosomes from the A genome and 9 from the B genome of wheat were recovered. The wheat chromosomes were monosomic except for five plants which were disomic, viz. 1A and 5A in two plants each, and a translocated 3AS/5AL in one plant. In 235 BC1 F3 plants, 174 wheat addition and substitution chromosomes were found, 143 from the A genome and 31 from the B genome. All wheat chromosomes except 3A from the A genome and four chromosomes from the B genome - 2B, 3B, 5B and 7B were recovered. The number of substitutions ranged from one to four per plant, only two plants having four. In the group of addition plants the number of added wheat chromosomes ranged from one to two, and in the case of addition substitution plants - from two to four.Wheat chromosomes occurred in monosomic form, except 10 plants. Six substitution plants were disomic for 1A, 2A, 5A, 7A, 2B and 3B, respectively. One was disomic for 1A and 5A in two addition plants. Two addition substitution plants were double disomic: 1A and 5A - in one, and 1A and 3B in the other. In the BC1 F3 generation, 23 different translocations were found, four of which occurred between wheat chromosomes and the remaining 19 - between wheat and rye chromosomes. Translocated chromosomes were monosomic, except four plants. Two of them were disomic for 3AS/4RL, one for 4AS/4RS and one for 7AS/7RS. The fertility of both addition and substitution plants ranged from 0 to 38.0 seeds/spike, regardless of the chromosome number, with a mean of 9.61 seeds/spike. Plants with 28 chromosomes showed singnificantly higher fertility than plants with 29 and more chromosomes, except additoion plants with chromosomes 5A and 5B. The analysis of the influence of particular wheat chromosomes on plant fertility showed that both substitution and addition plants with chromosome 6A had the highest average fertility, while plants with chromosome 2B in substitution lines as well as plants with chromosome 2A in addition and addition substitution lines had the lowest fertility .
We present twenty-nine PHEX gene mutations extending our previous work, giving it to a total of 37 different mutations identified in Polish patients with familial or sporadic X-linked hypophosphatemia. Deletions, insertions and nucleotide substitutions leading to frameshift (27%), stop codon (29%), splice site (24%), and missense mutations (20%) were found. The mutations are distributed along the gene, exons 3, 4, 11, 12, 14, 15, 17, 20 and 22 are regions with the most frequent mutation events. Four mutations, P534L, G579R, R549X and IVS15+1nt, recurred in three, four, two and three unrelated patients, respectively. They have also been detected in affected persons from other countries. Twenty-eight mutations are specific for Polish population and almost all of them are unique. Most of the identified mutations are expected to result in major changes in protein structure and/or function.
In tetraploid rye with single-substitution wheat chromosomes - 1A, 2A, 5A, 6A, 7A, 3B, 5B, 7B - chromosome pairing was analysed at metaphase I in PMCs with the C-banding method. The frequency of univalents of chromosome 1A was considerably higher than that of the other four wheat chromosomes of genome A (6A, 5A, 7A and 2A). Among chromosomes of genome B, the lowest mean frequency of univalents was observed for chromosome 5B. In monosomic lines, wheat chromosomes 1A, 2A, 5A, 6A, 7A and 5B paired with rye homoeologues most often in rod bivalents and in chain quadrivalents (also including 3B). The 47% pairing of 5B-5R chromosomes indicate that the rye genomes block the suppressor Ph1 gene activity. In monosomic plants with chromosomes 5A, 2A, 6A, 7A and 5B, a low frequency of rye univalents was observed. It was also found that the wheat chromosomes influenced the pairing of rye genome chromosomes, as well as the frequency of ring and rod bivalents and tri- and quadrivalents. However, the highest number of terminal chiasmata per chromosome occurred in the presence of chromosomes 5A and 2A, and the lowest ? in the presence of chromosomes 3B and 7B. In the presence of chromosome 5B, the highest frequency of bivalents was observed. The results of the present study show that the rye genome is closer related to the wheat genome A of than to genome B. The high pairing of wheat-rye chromosomes, which occurs in tetraploid rye with substitution wheat chromosomes, indicates that there is a high probability of incorporating wheat chromosome segments into rye chromosomes.
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