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The benefits of diploidy are considered to involve masking partially recessive mutations and increasing genetic diversity. Here, we review new studies showing evidence for diverse allele-specific expression and epigenetic states in mammalian brain cells, which suggest that diploidy expands the landscape of gene regulatory and expression programs in cells. Allele-specific expression has been thought to be restricted to a few specific classes of genes. However, new studies show novel genomic imprinting effects that are brain-region-, cell-type- and age-dependent. In addition, novel forms of random monoallelic expression that impact many autosomal genes have been described in vitro and in vivo. We discuss the implications for understanding the benefits of diploidy, and the mechanisms shaping brain development, function, and disease.

Noncanonical genomic imprinting can cause biased expression of one parental allele in a tissue; however, the functional relevance of such biases is unclear. To investigate ethological roles for noncanonical imprinting in dopa decarboxylase (Ddc) and tyrosine hydroxylase (Th), we use machine learning to decompose naturalistic foraging in maternal and paternal allele mutant heterozygous mice. We uncover distinct roles for the maternal versus paternal alleles on foraging, where maternal alleles affect sons while daughters are under paternal allelic control. Each parental allele controls specific action sequences reflecting decisions in naive or familiar contexts. The maternal Ddc allele is preferentially expressed in subsets of hypothalamic GABAergic neurons, while the paternal allele predominates in subsets of adrenal cells. Each Ddc allele affects distinct molecular and endocrine components of the brain-adrenal axis. Thus, monoaminergic noncanonical imprinting has ethological roles in foraging and endocrine functions and operates by affecting discrete subsets of cells.

MnAlNi powder was prepared by the process of vacuum levitation melting and high-energy ball milling, The morphology and phase structure of the powder were analyzed by Scanning Electron Microscope(SEM), X-ray diffraction(XRD) and the effect of the Ni content on microwave absorbing properties of MnAl powder was investigated by an vector network analyzer. The addition of Ni, which improved the microwave absorbing properties of MnAl powder but not changed the composition of Al 8 Mn 5 alloy. The minimum reflectivity of (Al 8 Mn 5 ) 0.95 Ni 0.05 powder with a coating thickness ( d ) of 1.8 mm was about −40.8 dB and has better bandwidth effect, the absorbing mechanism of AlMnNi powders on the electromagnetic was related to the electromagnetic loss within the absorbing coatings and the effect of coating thickness on the interference loss of electromagnetic wave.

SummaryHere, we describe an RNA-sequencing (RNA-seq)-based approach that accurately detects even modest maternal or paternal allele expression biases at the tissue level, which we call noncanonical genomic imprinting effects. We profile imprinting in the arcuate nucleus (ARN) and dorsal raphe nucleus of the female mouse brain as well as skeletal muscle (mesodermal) and liver (endodermal). Our study uncovers hundreds of noncanonical autosomal and X-linked imprinting effects. Noncanonical imprinting is highly tissue-specific and enriched in the ARN, but rare in the liver. These effects are reproducible across different genetic backgrounds and associated with allele-specific chromatin. Using in situ hybridization for nascent RNAs, we discover that autosomal noncanonical imprinted genes with a tissue-level allele bias exhibit allele-specific expression effects in subpopulations of neurons in the brain in vivo. We define noncanonical imprinted genes that regulate monoamine signaling and determine that these effects influence the impact of inherited mutations on offspring behavior.

Background Mixed chimerism with long-term composite tissue allotransplant (CTA) acceptance can be achieved through allogeneic bone marrow transplantation (BMT). The present study investigated the optimal chimerism level by giving different irradiation dosages to recipients to induce tolerance to CTA. Methods Chimera were prepared using Brown-Norway and Lewis rats with strong major histocompatibility complex incompatibility. The Lewis rats received 5 mg antilymphocyte globulin (day −1 and 10) and 16 mg/kg cyclosporine (day 0–10) and were separated into groups 1, 2, 3, 4, and 5 according to the day −1 irradiation dosage: 0, 200, 400, 600, and 950 cGy, respectively. The Lewis rats were then reconstituted with 100 × 10 6 T-cell–depleted Brown-Norway bone marrow cells (day 0) and received vascularized Brown-Norway-CTA on day 28. Chimerism was assessed monthly by flow cytometry starting on day 28 after BMT. Graft- versus -host disease (GVHD) was assessed clinically and histologically. Results Chimerism, 4 weeks after BMT, averaged 0.2%, 9.2%, 30.7%, 58%, and 99.3% in groups 1 to 5, respectively. GVHD occurred as follows: groups 1 and 2, none; group 3, 1 case of GVHD; group 4, 7 cases of GVHD (of which 3 died); and group 5, 10 cases of GVHD (of which 6 died). The percentage of long-term CTA acceptance was 0%, 0%, 90%, 70%, and 40% in groups 1 to 5, respectively. The percentage of regulatory T cells was significantly lower in high-chimerism (≥20%, n = 15) than in low-chimerism ( n = 5) rats that accepted CTA long-term . Conclusions The chimerism level correlated positively with GVHD occurrence and long-term CTA acceptance but correlated negatively with regulatory T-cell levels. Optimal chimerism for CTA acceptance through pre-CTA BMT and irradiation occurs at 20–50% at day 28 after BMT in the rat model.

Oral submucous fibrosis causes health-related and social problems for affected patients. Free flap reconstruction has proved effective for maintaining mouth opening after release of fibrosis. Two independent free flaps from separate donor sites, such as bilateral forearm flaps or bilateral anterolateral thigh (ALT) flaps, were traditionally required for reconstruction. The former option sacrifices one of the two major arteries in the forearm. Both options are time consuming and required two donor sites. To eliminate these disadvantages, we developed a technical modification that allows harvesting of two independent flaps from one ALT thigh based on one descending branch of the lateral circumflex femoral artery (d-LCFA). Eighteen flaps from nine donor sites were harvested for post-release reconstruction of oral submucous fibrosis. Mean flap size was 4.1 x 7.5 cm, mean pedicle length was 7.6 cm, mean ischaemia time was 104 min and mean total operation time was 13 h and 19 min. All donor sites were closed primarily, with one exception. One flap failed and was replaced with a contralateral ALT flap. One patient developed a wound infection and another developed a seroma at the recipient site. Four flaps required secondary de-bulking in three patients. The improvement in mouth opening was evaluated by inter-incisor distance (IID): mean preoperative IID was 9.6mm (range: 0-20mm), mean follow-up time was 16.2 months (range: 10-33 months); mean postoperative IID was 23.8mm and mean improvement in IID was 15.3mm (range: 10-27 mm). In conclusion, two independent flaps can be harvested from d-LCFA of the same thigh, instead of from both thighs, to reconstruct bilateral buccal defects after release of submucous fibrosis and/or contracture.

With the development of modern microsurgical reconstruction, there are several alternative methods for the complicated head and neck defect or injured extremity. The double-paddled flap, double flaps, and double flap with vascular flow-through linkage are good tools for extensive wide, composite, and three-dimensional defects. When faced with a difficult reconstruction, the expense, morbidity of the donor site, and operative time must be taken into consideration. Compared with other combined composite flaps and other methods, the chimeric flap has many advantages including: easy three-dimensional insetting, acceptable aesthetic appearance, reduced donor site morbidity, design with the least effort and operation time, and one pair of recipient vessel. The disadvantages of the chimeric flaps include: the variation of perforators, the requirement of a learning curve, and, sometimes, the need for a second venous drainage or shifting to double flaps. Overall, in selected cases, the chimeric flap is a good option for the reconstruction of extensive, composite, and three-dimensional defects.