The community of botanists in Mexico (and in the world) is celebrating the 75th anniversary of the journal Botanical Sciences , formerly Boletín de la Sociedad Botánica de México .
Crooke cell change was first found in the regressed and suppressed corticotroph (adrenocorticotropic hormone-producing) cells, and now is known to occur in pituitary tumors. The tumor cells of this ...type can be recognized by morphology with immunohistochemistry, and are well known to predict aggressive behavior such as invasion and rare metastases. This is one of the representative neuroendocrine tumors in the pituitary which is now considered to have malignant potential as proposed in the pancreas and gastrointestinal tracts. It is important to emphasize the pituitary tumor pathology such as Crooke cell change for prognostication and appropriate therapies. This review article describes the evolution from the Crooke cells to Crooke cell tumors which is timely along with the Fifth WHO classification 2022 published online.
Prolactin and growth hormone can acquire anti-angiogenic properties after undergoing proteolytic cleavage by Cathepsin D and bone morphogenetic protein 1 (BMP-1) into fragments known as vasoinhibins. ...Little is known about the effect of vasoinhibins on angiogenesis through the involvement of key cleavage enzymes Cathepsin D and BMP-1 in pituitary neuroendocrine tumors (PitNETs, formerly pituitary adenomas). The purpose of this study was to investigate the mechanism of action of Cathepsin D and BMP-1 on angiogenesis in PitNETs compared with that of pro-angiogenic factors, including vascular endothelial growth factor (VEGF) and basic fibroblast growth factor-2 (FGF2). A total of 43 patients were enrolled in a retrospective analysis and 22 samples were suitable for RNA extraction, including 16 nonfunctional PitNETs and six somatotroph tumors. The mRNA and protein levels of Cathepsin D, BMP-1, VEGF, and FGF2 were compared with those of von Willebrand factor, which was assessed to determine the vascularization of PitNETs. Cathepsin D and FGF2 were significantly correlated with vascularization in PitNETs. Both Cathepsin D and FGF2 are highly involved in angiogenesis in PitNETs, although the effect of Cathepsin D as an anti-angiogenic factor is dominant over that of FGF2 as a pro-angiogenic factor.
The prevailing view that insects lack endogenous enzymes for plant cell wall (PCW) digestion had led to the hypothesis that PCW digestion evolved independently in different insect taxa through the ...establishment of symbiotic relationships with microorganisms. However, recent studies reporting endogenous PCW-degrading genes and enzymes for several insects, including phylogenetically basal insects and closely related arthropod groups, challenge this hypothesis. Here, we summarize the molecular and biochemical evidence on the mechanisms of PCW digestion in insects to analyze its evolutionary pathways. The evidence reveals that the symbiotic-independent mechanism may be the ancestral mechanism for PCW digestion. We discuss the implications of this alternative hypothesis in the evolution of plant-insect interactions and suggest that changes in the composition of lignocellulolytic complexes were involved in the evolution of feeding habits and diet specializations in insects, playing important roles in the evolution of plant-insect interactions and in the diversification of insects.
Oak species (Fagaceae: Quercus) differ in their distribution at the landscape scale, specializing to a certain portion of environmental gradients. This suggests that functional differentiation favors ...habitat partitioning among closely related species. To elucidate the mechanisms of species coexistence in oak forests, we explored patterns of interspecific variation in functional traits involved in water-use strategies. We tested the hypothesis that oak species segregate along key trade-offs between xylem hydraulic efficiency and safety, and between hydraulic safety and drought avoidance capacity, leading to species niche partitioning across a gradient of aridity. To do so, we quantified biophysical and physiological traits in four red and five white oak species (sections Lobatae and Quercus, respectively) across an aridity gradient in central Mexico. We also explored the trade-offs guiding species differentiation, particularly between the drought tolerance versus water acquisition capacity, and determined whether the water-use strategy was associated with the portion of the environmental gradient that the species occupy. In a trait-by-trait analysis, we detected differences between white and red oak species. However, a larger part of the variation was explained at the species rather than at the section level. We detected two primary axes of trait covariation. The first exhibited differences between species with dense tissues and species with soft tissues (the tissue construction cost axis); however, the oak sections did not constitute separate groups, while the second suggested a trade-off between xylem resistance to cavitation and tree deciduousness. As expected, the water-use strategies of the species were related to the environment; oak species from arid areas had more deciduousness and a higher instantaneous water-use efficiency. In contrast, their humid counterparts had less deciduousness and had a xylem that was more resistant to embolisms. Altogether, these results suggest that aridity filters closely related species, resulting in habitat partitioning and niche divergence.
Most pituitary adenoma/neuroendocrine tumours (PitNET) are histologically benign and grow slowly; however, a subset of these tumours exhibit a more aggressive clinical course characterized by local ...invasiveness and early recurrence. These high-risk PitNETs often require multiple surgeries and radiation over several years and may eventually acquire carcinomatous characteristics, such as metastasis in some cases. Herein, we report a rare case of PitNET causing oculomotor paresis with extremely rapid recurrence only 3 months after initial surgery, followed by lethal liver metastasis. Preoperative magnetic resonance imaging and intraoperative findings were consistent with typical PitNETs, other than moderate invasion of the cavernous sinus. Pathological examination of the specimen obtained from the initial transsphenoidal surgery revealed increased mitosis and elevated rates of cells positive for Ki-67 and p53. Based on the immunohistochemical assessment for transcription factors and pituitary hormones, the diagnosis was determined to be a silent sparsely granulated corticotroph PitNET with focal malignant transformation. Aggressive features represented by Ki-67 and p53 positivity were more robust in recurrent and metastatic specimens, but hormone immunostaining was decreased. Epigenetic analysis revealed methylation of the telomerase reverse transcriptase (
) promoter in the tumour, resulting in TERT upregulation. Despite extensive research, markers for distinguishing extremely aggressive PitNETs have not been determined. Although further analysis is needed, our case demonstrates the possible usefulness of assessing
promoter methylation status in the stratification of recurrence risk in extremely high-risk variants of PitNET.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Phylogenetic structure was clustered but tended to random as succession advanced.•Fabales determined the phylogenetic clustering mainly in first years of succession.•Effects of global climatic ...change on Fabales could impact the plant community dynamic.•Severe drought could increase phylogenetic distance and phylodiversity on dead component.•Abiotic and stochastic processes could be major mechanisms in our successional system.
Phylogenetic analysis of plant communities is useful for inferring ecological mechanisms driving forest succession. However, such analysis has scarcely been undertaken in tropical dry environments, especially for the dynamics of demographic components (i.e., recruited, surviving and dead plants) affecting the successional process. Here, we combine chronosequence and dynamic data to study the role of habitat filtering and limiting similarity in the old-field succession of a seasonal tropical dry forest subjected to strong climatic events (e.g., the El Niño Southern Oscillation (ENSO) and heavy rains). We documented successional changes in the phylogenetic structure and phylodiversity of regenerative communities (shrubs and trees ≤ 1 m in height), assessed phylogenetic changes in demographic components during succession, and explored the effects of interannual rainfall variation on such changes. Over five years, we monitored the dynamics of regenerative plant communities in a chronosequence of nine abandoned pastures (fallow age of 0–12 years) and three old-growth sites. For each year and site, we quantified changes in the standardized mean phylogenetic distance (MPD.OBS.Z) and phylodiversity (PD) of entire regenerative communities and recruited, surviving and dead plants. For each phylogenetic metric and demographic component, we assessed the effect of successional age, time (years), and interannual rainfall variation. Large variation in MPD.OBS.Z and PD was observed among sites and years, especially in the recently abandoned pastures. Overall, the phylogenetic community structure was clustered early in succession and became more random as succession advanced. Species from the order Fabales made especially strong contributions to the phylogenetic clustering, especially during the first years of succession. In dead plants, the MPD.OBS.Z and PD increased in the drier year due to the high mortality of plants from several clades (orders). The high prevalence of clustered and random phylogenetic structure suggests that abiotic filtering and stochastic processes are major structuring mechanisms in this successional system. Due the strong contribution of Fabales in the phylogenetic structure of regenerative communities of tropical dry forest, the effects of strong climatic events (e.g., ENSO) on Fabales could influence the old-field succession of tropical dry forests.
Three new species of oak gall wasps of the genus
Amphibolips
Reinhard, 1865 (Hymenoptera: Cynipidae: Cynipini) are described from Mexico:
Amphibolips magnigalla
Nieves-Aldrey & Castillejos-Lemus,
...Amphibolips kinseyi
Nieves-Aldrey & Castillejos-Lemus and
Amphibolips nigrialatus
Nieves-Aldrey & Castillejos-Lemus. The specimens of the first two species were representative of sexual generations and come from the State of Oaxaca, while only a female, collected in the State of Veracruz, is described for
A. nigrialatus
. The new species induces galls on
Quercus zempoaltepecana
and
Q. sapotifolia
(Fagaceae, section Lobatae, red oaks). Descriptions of the diagnostic morphological characteristics of the three species and a key for their identification are provided. The taxonomic relationships of the new species with other species of
Amphibolips
are discussed; the three new species are closely allied amongst themselves and are related to
A. dampfi
Kinsey, 1937. With the three newly-described species, the number of
Amphibolips
in Mexico is increased to 23.
Quercus
is the most diverse genus of ectomycorrhizal (ECM) host plants; it is distributed in the Northern and Southern Hemispheres, from temperate to tropical regions. However, their ECM communities ...have been scarcely studied in comparison to those of conifers. The objectives of this study were to determine the richness of ECM fungi associated with oak forests in the Cuitzeo basin in southwestern Mexico; and to determine the level of richness, potential endemism and species similarity among ECM fungal communities associated with natural oak forests worldwide through a meta-analysis. The ITS DNA sequences of ECM root tips from 14 studies were included in the meta-analysis. In total, 1065 species of ECM fungi have been documented worldwide; however, 812 species have been only found at one site. Oak forests in Europe contain 416 species, Mexico 307, USA 285, and China 151. Species with wider distributions are Sebacinaceae sp. SH197130,
Amanita subjunquillea
,
Cenococcum geophilum
,
Cortinarius decipiens
,
Russula hortensis
,
R. risigallina
,
R. subrubescens
, Sebacinaceae sp. SH214607,
Tomentella ferruginea
, and
T. lapida.
The meta-analysis revealed (1) that Mexico is not only a hotspot for oak species but also for their ECM mycobionts. (2) There is a particularly high diversity of ECM Pezizales in oak seasonal forests from western USA to southwestern Mexico. (3) The oak forests in southwestern Mexico have the largest number of potential endemic species. (4) Globally, there is a high turnover of ECM fungal species associated with oaks, which indicates high levels of alpha and beta diversity in these communities.
Connectivity is a landscape property that promotes gene flow between organisms located in different patches of habitat and provides a way to reduce habitat loss by maintaining flux of organisms ...through the landscape; it is an important factor for conservation decisions. In this study, we evaluated the structural and functional connectivity among 510 oak forest remnants in a basin in central Mexico by modeling the potential distribution of seven oak species that inhabit in it. The structural and functional connectivity of oak forest remnants was estimated by graph theory. Distribution models for all the oak species had a good level of predictability, showing that 53.16% of the basin is suitable for oaks. The importance for connectivity varied between the remnant forests. Large forest fragments had the highest values of connectivity, and small forest fragments acted as steppingstones favoring the movement of organisms among fragments. In the southern region of the basin, connected remnant forests had conformed to a large network, but in the northern region, the remnant forests were mostly isolated. Conservation of oak forests in this basin requires protection for remaining patches by preserving both large and small ones and restoring biological corridors to reduce the isolation of forest fragments.
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