HLA Haplotypes with C4B5; evidence for further allelic heterogeneity

Twenty-three individuals from various disease groups and normal controls were identified by immunofixation with anti-C4, C4-dependent lysis, determination of Rg (Rodgers) and Ch (Chido) phenotypes, and immunoblotting with C4-specific mouse monoclonal antibody. We found that one haplotype predominates with the C4B ^* 5 allele, HLA-A11, B22(55), Cw3, Bf ^* S, C4A ^* 4B ^* 5, which also carries the Ch ^{1,–2, 3} haplotype. The B5 allotype was also found with HLA-1360, HLA-1335 in Caucasoids, and HLA-B18 in non-Caucasoids; these carried the Ch ^{–1, –2, –3} haplotype. Our results are in accord with an earlier report of two B5 subtypes, B5Rg⁺ and B5Rg^– (Roos et al. 1984). The specificity of the mouse monoclonal antibodies IC4 and 21312 had been previously related to C4A and C4B, respectively, but our results suggest that they relate more closely to Rg and Ch determinants.     

Ultrastructure of Human labial salivary glands

Summary Human labial salivary glands, obtained by biopsy from 32 subjects, were studied by light and electron microscopy. Intranuclear inclusions, unrelated to nucleoli, were present in many of the acinar nuclei in glands from 16 of the 32 donors. More than one inclusion was sometimes observed within a single nucleus. They measured about 1 in diameter, and were stainable in a variety of ways. They were eosinophilic, some were stained by Nile blue sulphate, some were PAS-positive, and all were Feulgen-negative. They were bounded by a single membrane, which never exhibited continuity with the nuclear envelope, and they showed considerable morphological variation. The more complex inclusions consisted of alternating shells of light and dark material with tiny dense granules embedded in the latter. The intranuclear inclusions, which apparently were non-viral in origin, were in some way related to the secretory cycle of the mucous cells, since they were found only in immature cells, and never in cells in which secretory products were abundant.This work was supported in part by grants from the Henry Spenadel Trust and the Max C. Fleischmann Foundation of Nevada, by grant CA-08748 from the National Cancer Institute, by grant 5 SO1 FR 05335-07 from the National Institutes of Health, by a grant from the National Cystic Fibrosis Research Foundation, and by an Institutional Grant to the School of Dental and Oral Surgery, Columbia University, from the National Institutes of Health.The authors are indebted to Dr.Louis Mandel for performing the biopsies used in this study. The expert technical assistance of Mrs.Mona Seggio is acknowledged.     

Order-disorder phenomena in myelinated nerve sheaths. II. The structure of myelin in native and swollen rat sciatic nerves and in the course of myelinogenesis

The algorithm described in the accompanying paper was applied to X-ray scattering experiments performed with rat sciatic nerves, either as a function of the age of the animal (4 to 30 days), or with adult nerves swollen in non-isotonic media. The results were all consistent with the model of disorder used in the theoretical treatment. The algorithm leads, in one step, from the data to the numerical values of the parameters, avoiding all intermediate manipulation. For each experiment a variety of parameters was determined: the average D and the variance sigma 2D of the repeat distance, the average number [N] of motifs per crystallite, the set [idiff(h/D)], which defines the diffuse scattering, the fraction alphaloose of myelin that does not belong to the compact sheaths, and the set [imotif (k/2D)], which suffices to define the continuous intensity curve of the motif imotif(s). Note the remarkable wealth of information, especially by contrast with conventional analyses which, as a rule, only yield the values of D and of the set [imotif(h/D)] (insufficient to determine the function imotif(s]. The function imotif(s) and the parameters D and sigma D (and thus the local structure of the myelin sheaths) were shown to be almost invariant in the course of myelinogenesis; what varies is mainly the total amount of myelin in the nerve and the number of membranes per sheath. Swelling agents have a dramatic influence on the X-ray scattering spectra, but in spite of the conspicuous variation of D, sigma D and [N] the structure of the motif is invariant. The structure of the motif was shown to be quite different in the native and in the swollen samples; the stacking disorder appears to involve mainly the cytoplasmic space in native myelin, the external space in swollen nerves. The very notion of electron density profile, when disorder is present, is discussed. Two criteria were proposed to select the "best" signs of the reflections: two sets came out at almost the same rank, one corresponding to Caspar & Kirschner's the other to Worthington & McIntosh's proposals, neither of which can be ruled out according to the criteria used in this work.     

Arg74 in HLA-DRBI and DRB3 controls a DR3-related epitope

TR81 is a specificity closely related to or identical with DR3. In Caucasoids two amino acids, Tyr at position 26 and Arg at position 74 of HLA class II DR chains, have been found to be associated with the presence of TR81. Recently, a variant of DRBI *03 identified in American Blacks has been shown to possess Arg at position 74 but Phe at position 26. This codon combination is found to be present in four other cell lines where it still specifies the TR81 determinant. This suggests that the TR81 specificity is uniquely dependent on the presence of Arg at position 74.     

Xp-duplications with and without sex reversal

Duplications in Xp including the DSS (dosage sensitive sex reversal) region cause male to female sex reversal. We investigated two patients from families with Xp duplications. The first case was one of two sisters with karyotype 46,XY, der(22), t(X;22)(p11.3;p11)mat and unambiguous female genitalia. The living sister was developmentally retarded, and showed multiple dysmorphic features and an acrocallosal syndrome. The second case was a boy with a maternally inherited direct duplication of Xp21.3-pter with the breakpoint close to the DSS locus. He had multiple abnormalities and micropenis, but otherwise unambiguous male genitalia. We performed quantitative Southern blot analysis with probes from Xp22.13 to p21.2 to define the duplicated region. Clinical, cytogenetic, and molecular data from both patients were compared with those of previously reported related cases. A comparison of the extragenital symptoms revealed no differences between patients with or without sex reversal. In both cases, the symptoms were non-specific. Among 22 patients with a duplication in Xp, nine had unambiguous female genitalia and a well-documented duplication of the DSS region. Two patients with duplication of DSS showed ambiguous external genitalia. From these data, we conclude that induction of testicular tissue may start in these patients, but that the type of genitalia depends on the degree of subsequent degeneration by a gene in DSS.     

Expressed Peromyscus maniculatus (Pema) MHC class I genes: evolutionary implications and the identification of a gene encoding a Qa1-like antigen

To gain insight into the evolution of rodent major histocompatibility complex (MHC) class I genes and identify important (conserved) nonclassical class I (class Ib) gene products and residues in these proteins, sixPeromyscus maniculatus MHC (Pema) class I cDNA clones were isolated and sequenced. FivePema class I cDNAs appeared most similar to mouse and rat classical class I (class Ia) genes. One exhibited highest similarity to anH2 class Ib gene,H2-T23 (encoding the Qa1 antigen). Phylogenetic trees constructed withPema, RT1, andH2 class I sequences suggested that the lineages of some rodent class Ib genes (e.g.,T23 andT24) originated prior toMus andPeromyscus speciation [>50 million years (My) ago]. Sequences of four Qa1-like proteins from three species permitted the identification of ten Qa1-specific amino acids. On the basis of molecular modeling, three residues showed the potential to interact with T-cell receptors and three residues (all corresponding to polymorphic positions among H2 class Ia proteins) were predicted to influence antigen binding. The recognition of mouse Qa1 proteins by a subset of T-cells in influenced by a locus,Qdm, which encodes the H2-D leader peptide. One of thePema class I cDNA clones classified asH2-K, D/L-like (class Ia) is predicted to encode an identical peptide, implying that an antigen binding protein (Qa1) and the antigen to which it binds (the product ofQdm) has been conserved for over 50 My. The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession numbers U12822 (Pm13), U12885 (Pm41), U12886 (Pm52), U12887 (Pm62), U16846 (Pm11), and U16847 (Pm53)     

Artificial hybridization within Saxifraga pentadactylis (Saxifragaceae)

Saxifraga pentadactylis subsp. almanzorii , an endemic to the subalpine nucleus of Sierra de Gredos (central Spain), differs from its closest relative, subsp. willkommiana , by its less showy petals. An artificial crossing program was carried out in order to assess the degree of reproductive isolation between the subspecies. To facilitate interpretation of the results, the program was extended to 10 other interspecific hybrid combinations within sect. Saxifraga . All the data gathered are congruent with the occurrence of two evolutionary scenarios. Interspecific crossings, rendering moderate to high seed-set (in obtaining the F₁), and vigorous but relatively sterile F₁ offspring, reveal reproductive barriers at the level of the F₁ fertility, probably originated as a byproduct of divergent evolution. In contrast, intraspecific crossings within S. pentadactylis resulted in seed-set values lower than expected (in obtaining the F₁), in a majority of weak non-viable F₁ offspring but also in a few fertile F₁ hybrid specimens which were able to originate F₂ offspring. This second pattern reveals reproductive barriers at the level of the F₁ vitality, probably arisen in a quite abrupt fashion. The lower P/O for subsp. almanzorii as compared to subsp. willkommiana , together with the rest of the evidence suggest that the reproductive barriers between them might be the product of active selection against hybridization achieved by incrementing the levels of autogamy in the former.     

H-2T24 and Pema T24: orthologous expressed MHC class Ib genes from mouse and Peromyscus maniculatus

The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession numbers U03104 and L22338.