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•Mitochondrial DNA (mtDNA) copy number and telomere length (TL) correlates in blastocysts.•Paternal aging affects the mtDNA and TL in blastocysts.•Paternal aging affects the mtDNA in ...issues of offspring.
Mitochondrial DNA (mtDNA) copy number and telomere length (TL) in blastocysts derived from the same male mice at young (10–19-week-old) and aged (40–49-week-old) time points and mtDNA and TL in the hearts of offspring derived from young and aged male mice were examined. Paternal aging correlated with reduced mtDNA and TL in blastocysts. mtDNA and TL were significantly correlated, which was also observed in bovine blastocysts. Moreover, mtDNA in the heart of offspring was reduced in male mice with paternal aging. In conclusion, paternal aging affects embryonic mtDNA and TL, potentially impacting their offspring.
Mouse spermatogenesis, from spermatogonial stem cell proliferation to sperm formation, can be reproduced in vitro by culturing testis tissue masses of neonatal mice. However, it remains to be ...determined whether this method is also applicable when testis tissues are further divided into tiny fragments, such as segments of the seminiferous tubule (ST), a minimal anatomical unit for spermatogenesis. In this study, we investigated this issue using the testis of an Acrosin-GFP/Histone H3.3-mCherry (Acr/H3) double-transgenic mouse and monitored the expression of GFP and mCherry as indicators of spermatogenic progression. Initially, we noticed that the cut and isolated stretches of ST shrunk rapidly and conglomerated. We therefore maintained the isolation of STs in two ways: segmental isolation without truncation or embedding in soft agarose. In both cases, GFP expression was observed by fluorescence microscopy. By whole-mount immunochemical staining, meiotic spermatocytes and round and elongating spermatids were identified as Sycp3-, crescent-form GFP-, and mCherry-positive cells, respectively. Although the efficiency was significantly lower than that with tissue mass culture, we clearly showed that spermatogenesis can be induced up to the elongating spermatid stage even when the STs were cut into short segments and cultured in isolation. In addition, we demonstrated that lowered oxygen tension was favorable for spermatogenesis both for meiotic progression and for producing elongating spermatids in isolated STs. Culturing isolated STs rather than tissue masses is advantageous for explicitly assessing the various environmental parameters that influence the progression of spermatogenesis.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
ABSTRACT
We examined variations in age at seaward migration and sea age for the anadromous form of red‐spotted masu salmon (Oncorhynchus masou ishikawae) in two Japanese rivers. The anadromous form ...of red‐spotted masu salmon expressed only two sea migration patterns in the two rivers: (a) the majority of the salmon (95%, n = 81) were of age‐0, and age‐1 migrants were rare (n = 4); and (b) all the salmon examined (n = 22) made a return migration within a year, with 23% of the salmon exhibiting potamodromy in the river. Owing to low variation in their sea migratory patterns, the anadromous form of red‐spotted masu salmon is likely vulnerable to environmental fluctuations.
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•The 2-naphthylmethoxymethyl group can be removed in the presence of 1-naphthylmethoxymethyl group with DDQ.•1-Naphthylmethoxymethyl chloride is more readily prepared than ...2-naphthylmethoxymethyl chloride.•Naphthylmethoxymethyl groups are compatible with strong acids even in the presence of hard nucleophiles.
1-Naphthylmethyl (NAPI) and 1-naphthylmethoxymethyl (NAPOMI) protecting groups were developed as new members of the benzyl- and benzyloxymethyl-type family. NAPI and NAPOMI can be introduced under conventional conditions, such as NAPIBr/NaH/room temperature (rt), or NAPOMICl/i-Pr2EtN/rt. They can also be removed under conventional conditions, e.g., by dichlorodicyanobenzoquinone (DDQ)- or ceric ammonium nitrate (CAN)-mediated oxidation, or by hydrogenolysis. The specific advantages of these new protecting groups are: i) a less costly synthesis of NAPOMICl compared to NAPOMIICl, ii) the possibility to remove NAPOMII selectively in the presence of NAPOMI by DDQ-mediated oxidation, and iii) the compatibility with strong acids even in the presence of hard nucleophiles.
A search for early response genes that are activated following germ cell induction from mouse embryonic stem cells in vitro led us to the isolation of a long noncoding RNA that contains a SINE (short ...interspersed element)-B1F motif that was named R53. In situ hybridization and northern blot analyses revealed that the R53 subfragment RNA bears a B1F motif, is processed from the primary transcript, is expressed in adult testis and is predominantly localized in meiotic metaphase chromatin during spermatogenesis. Recent studies of chromosome-associated RNAs have explored novel functions of noncoding RNAs. Specifically, chromosome-bound noncoding RNAs function not only as structural components of chromosome but also as scaffolds that recruit epigenetic modulators for transcriptional regulation, and they are dynamically rearranged during the cell cycle. However, few studies have explored meiotic chromatin; thus, R53 RNA appears to be the first long noncoding RNA to be tightly associated with the metaphase chromatin during spermatogenesis. Furthermore, R53 knockdown using a lentivirus-mediated RNAi injected into mouse testis and organ culture of the fragments revealed a remarkable reduction in postmeiotic cells and irregular up-regulation of several postmeiotic genes, which suggests the possibility that the SINE-B1-derived noncoding RNA R53 plays an indispensable role in the transcriptional regulation of key spermatogenesis genes.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Thalamocortical (TC) connectivity is reorganized by thalamic inputs during postnatal development; however, the dynamic characteristics of TC reorganization and the underlying mechanisms remain ...unexplored. We addressed this question using dendritic refinement of layer 4 (L4) stellate neurons in mouse barrel cortex (barrel cells) as a model; dendritic refinement of L4 neurons is a critical component of TC reorganization through which postsynaptic L4 neurons acquire their dendritic orientation toward presynaptic TC axon termini. Simultaneous labeling of TC axons and individual barrel cell dendrites allowed in vivo time-lapse imaging of dendritic refinement in the neonatal cortex. The barrel cells reinforced the dendritic orientation toward TC axons by dynamically moving their branches. In N-methyl-D-aspartate receptor (NMDAR)-deficient barrel cells, this dendritic motility was enhanced, and the orientation bias was not reinforced. Our data suggest that L4 neurons have “fluctuating” dendrites during TC reorganization and that NMDARs cell autonomously regulate these dynamics to establish fine-tuned circuits.
•A general method for single-cell labeling/gene KO was developed•Layer 4 neuronal dendrites and TC axons were simultaneously visualized in neonates•Layer 4 neuronal dendrites are highly motile during TC circuit refinement•NMDARs cell autonomously regulate dendritic motility during TC circuit refinement
By two-photon time-lapse imaging of the barrel cortex in neonates, Mizuno et al. show that layer 4 neurons have fluctuating dendrites during thalamocortical circuit reorganization and that NMDARs cell autonomously regulate these dynamics to establish fine-tuned circuits.
We previously reported the successful induction and completion of mouse spermatogenesis by culturing neonatal testis tissues. The culture medium consisted of α-minimum essential medium (α-MEM), ...supplemented with Knockout serum replacement (KSR) or AlbuMAX, neither of which were defined chemically. In this study, we formulated a chemically defined medium (CDM) that can induce mouse spermatogenesis under organ culture conditions. It was found that bovine serum albumin (BSA) purified through three different procedures had different effects on spermatogenesis. We also confirmed that retinoic acid (RA) played crucial roles in the onset of spermatogonial differentiation and meiotic initiation. The added lipids exhibited weak promoting effects on spermatogenesis. Lastly, luteinizing hormone (LH), follicle stimulating hormone (FSH), triiodothyronine (T3), and testosterone (T) combined together promoted spermatogenesis until round spermatid production. The CDM, however, was not able to produce elongated spermatids. It was also unable to induce spermatogenesis from the very early neonatal period, before 2 days postpartum, leaving certain factors necessary for spermatogenic induction in mice unidentified. Nonetheless, the present study provided important basic information on testis organ culture and spermatogenesis in vitro.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We consider the Cauchy problem for the one dimensional nonlinear dissipative Schrödinger equation with a cubic nonlinearity
λ
|
u
|
2
u
, where
λ
∈
C
with Im
λ
<
0
. We show that a relation between
...L
2
-decay rate for the solution and a smoothness of the initial data. Our result improves the recent work of Hayashi–Li–Naumkin (Adv Math Phys Art. ID 3702738, 7, 2016) for the decay rate of
L
2
.
Iron and heme play very important roles in various metabolic functions in bacteria, and their intracellular homeostasis is maintained because high concentrations of free forms of these molecules ...greatly facilitate the Fenton reaction-mediated production of large amounts of reactive oxygen species that severely damage various biomolecules. The ferric uptake regulator (Fur) from
ATCC 17616 is an iron-responsive global transcriptional regulator, and its
deletant exhibits pleiotropic phenotypes. In this study, we found that the phenotypes of the
deletant were suppressed by an additional mutation in
The transcription of
was negatively regulated by Fur under iron-replete conditions and was constitutive in the
deletant. Growth of a
deletant was severely impaired in a medium containing hemin as the sole iron source, demonstrating the important role of HemP in hemin utilization. HemP was required as a transcriptional activator that specifically binds the promoter-containing region upstream of a Fur-repressive
operon, which encodes the proteins for hemin uptake. A
deletant was still able to grow using hemin as the sole iron source, albeit at a rate clearly lower than that of the wild-type strain. These results strongly suggested (i) the involvement of HmuR in hemin uptake and (ii) the presence in ATCC 17616 of at least part of other unknown hemin uptake systems whose expression depends on the HemP function. Our
analysis also indicated high-affinity binding of HemP to hemin, and such a property might modulate transcriptional activation of the
operon.
Although the
genes for the utilization of hemin as a sole iron source have been identified in a few
strains, the regulatory expression of these genes has remained unknown. Our analysis in this study using
ATCC 17616 showed that its HemP protein is required for expression of the
operon, and the role of HemP in betaproteobacterial species was elucidated for the first time, to our knowledge, in this study. The HemP protein was also found to have two additional properties that have not been reported for functional homologues in other species; one is that HemP is able to bind to the promoter-containing region of the
operon to directly activate its transcription, and the other is that HemP is also required for the expression of an unknown hemin uptake system.
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