An adventurous journey toward and away from fern apomixis: Insights from genome size and spore abortion patterns.

PREMISE: Apomixis in ferns is relatively common and obligatory. Sterile hybrids may restore fertility via apomixis at a cost of long-term genetic stagnation. In this study, we outlined apomixis as a possible temporary phase leading to sexuality and analyzed factors relating to transitioning to and away from apomixis, such as unreduced and reduced spore formation in apomict and apo-sex hybrid ferns. METHODS: We analyzed the genome size of 15 fern species or hybrids ("taxa") via flow cytometry. The number of reduced and unreduced gametophytes was established as a proxy for viable spore formation of either type. We also calculated the spore abortion ratio (sign of reduced spores) in several taxa, including the apo-sex hybrid Dryopteris × critica and its 16 apomictically formed offspring. RESULTS: Four of 15 sampled taxa yielded offspring variable in genome size. Specifically, each variable taxon formed one viable reduced plant among 12-451 sampled gametophytes per taxon. Thus, haploid spore formation in the studied apomicts was very rare but possible. Spore abortion analyses indicated gradually decreasing abortion (haploid spore formation) over time. In Dryopteris × critica, abortion decreased from 93.8% to mean 89.5% in one generation. CONCLUSIONS: Our results support apomixis as a transitionary phase toward sexuality. Newly formed apomicts hybridize with sexual relatives and continue to form haploid spores early on. Thus, they may get the genomic content necessary for regular meiosis and restore sexuality. If the missing relative goes extinct, the lineage gets locked into apomixis as may be the case with the Dryopteris affinis complex.

Morphological and functional evolution of gametophytes in epilithic Hymenasplenium murakami-hatanakae (Aspleniaceae): The fifth family capable of producing the independent gametophytes.

The fern independent gametophytes that can maintain populations by vegetative reproduction without conspecific sporophytes have been considered an unusual phenomenon found in some epiphytic or epilithic species of Hymenophyllaceae, Pteridaceae, Lomariopsidaceae, and Polypodiaceae. By chance, the discovery of mysterious strap-like gametophytes on Izu-Oshima Island, Japan, has led to the hypothesis that Hymenasplenium murakami-hatanakae, a fern species belonging to Aspleniaceae, can also form independent gametophytes. Our investigation revealed gametophyte populations of H. murakami-hatanakae on three islands in the Izu Islands. Based on chloroplast DNA analysis of the gametophyte and sporophyte populations, the gametophytes were found to be maintained by vegetative reproduction without a new supply of spores from sporophytes. A comparison of the surrounding vegetation at the collection sites showed that environmental factors such as light and humidity may influence the maintenance of gametophyte populations. These results clearly show that H. murakami-hatanakae is one of the ferns capable of forming independent gametophytes. This is the first report of independent gametophytes from the suborder Aspleniineae (eupolypod II). The discovery of the independent gametophyte within a phylogenetic lineage previously thought not to form independent gametophytes will provide important insights into the morphological and functional evolution of gametophytes in ferns.

Club-mosses (Diphasiastrum, Lycopodiaceae) from the Far East - Introgression and possible cryptic speciation.

Hybridization occurs often in the genus Diphasiastrum (Lycopodiaceae), which corroborates reports for the two other recognized lycophyte families, Isoëtaceae and Selaginellaceae. Here we investigate the case of D. alpinum and D. sitchense from the Russian Far East (Kamchatka). Their hybrid, D. × takedae, was morphologically recognizable in 16 out of 22 accessions showing molecular signatures of hybridization; the remaining accessions displayed the morphology of either D. alpinum (3) or D. sitchense (3). We sequenced markers for chloroplast microsatellites (cp, 175 accessions from Kamchatka) and for the two nuclear markers RPB and LFY (175 and 152 accessions). A selection of 42 accessions, including all hybrid accessions, was analysed via genotyping by sequencing (GBS). We found multiple, but apparently uniparental hybridization, clearly characterized by a deviating group of haplotypes for D. sitchense and all hybrids. All accessions showing molecular signatures of hybridization in nuclear markers revealed the parental haplotype of D. sitchense, however only the LFY marker differentiated between the parent species. GBS, including 69,819 quality-filtered single nucleotid polymorphisms, unambiguously identified the hybrids and revealed introgression to occur. Most of the hybrids were F1, but three turned out to be backcrosses with D. alpinum (one) and with D. sitchense (two). These observations are in contrast to prior findings on three European species and their intermediates where all three hybrids turned out to be independent F1 crosses without evidence of recent backcrossing. In this study, backcrossing was detected, which indicates a limited fertility of the hybrid taxon D. × takedae. A comparison of accessions of Kamchatkian D. alpinum with plants from Europe indicated possible cryptic speciation. Accessions from the Far East had (i) a lower DNA content (7.0 vs. 7.5 pg/2C), (ii) different prevailing cp haplotypes, and (iii) RPB genotypes, and (iv) a clearly different SNP pattern in GBS. Diphasiastrum sitchense and the similar D. nikoënse, for the latter additional accessions from Japan were investigated, appeared as forms of one diverse species, sharing genotypes in both nuclear markers, although chloroplast haplotypes and DNA content show slight variations.

Apomictic fern fathers: an experimental approach to the reproductive characteristics of sexual, apomict, and hybrid fern gametophytes.

PREMISE: Apomixis and hybridization are two essential and complementary factors in the evolution of plants, including ferns. Hybridization combines characteristics from different species, while apomixis conserves features within a lineage. When combined, these two processes result in apo-sex hybrids. The conditions leading to the formation of these hybrids are poorly understood in ferns. METHODS: We cultivated spores from 66 fern samples (43 apomicts, 7 apo-sex hybrids, and 16 sexuals), and measured their development in vitro over 16 weeks. We evaluated germination, lateral meristem formation rates, sexual expression, and production of sporophytes and then compared ontogenetic patterns among the three groups. RESULTS: The three examined groups formed antheridia (male gametangia) but differed in overall gametophyte development. Sexual species created archegonia (female, 86% of viable samples), but no sporophytes. Apomicts rarely created nonfunctional archegonia (8%) but usually produced apogamous sporophytes (75%). Surprisingly, apomictic and sexual species showed similar development speed. The sexually reproducing parents of viable studied hybrids formed about twice as many meristic gametophytes as the apomictic parents (39% vs. 20%, respectively). CONCLUSIONS: We present the most thorough comparison of gametangial development of sexual and apomictic ferns, to date. Despite expectations, apomictic reproduction might not lead to earlier sporophyte formation. Apomicts produce functional sperm and thus can contribute this type of gamete to their hybrids. The development patterns found in the parents of hybrids indicate a possible increase of hybridization rates by antheridiogens. The apo-sex hybrids always inherit the apomictic reproductive strategy and are thus capable of self-perpetuation.

Establishment of an allotetraploid fern species, Lepisorus yamaokae Seriz., between two highly niche-differentiated parental species.

PREMISE: The successful establishment of polyploid species is hypothesized to be promoted by niche differentiation from the parental species or by range shifts during climate oscillations. However, few studies have considered both of these factors simultaneously. We resolved the origin of a tetraploid fern, Lepisorus yamaokae, and explored a pattern of niche differentiation among the allotetraploid and parental species in past and current climates. METHODS: We reconstructed phylogenetic trees based on plastid marker and single-copy nuclear genes to resolve the allopolyploid origin of L. yamaokae. We also evaluated climatic niche differentiation among L. yamaokae and its two parental species using species distribution models in geographic space and principal component analysis. RESULTS: We infer that L. yamaokae had a single allotetraploid origin from L. annuifrons and L. uchiyamae. Climatic niche analyses show that the parental species currently occupy different niche spaces. The predicted distribution of the parental species at the Last Glacial Maximum (LGM) suggests more opportunities for hybridization during the LGM or during other recent temporary range shifts. Lepisorus yamaokae has a narrower niche than the additive niche of the parental species. We also observed niche conservatism in L. yamaokae. CONCLUSIONS: Range shifts of the parental species during climatic oscillations in the Quaternary likely facilitated the formation and establishment of L. yamaokae. Further, the genetic intermediacy of L. yamaokae may have enabled a niche shift in its microenvironment, resulting in its successful establishment without a macroclimatic niche shift in L. yamaokae.

Reticulate evolution in the apogamous Dryopteris varia complex (Dryopteridaceae, subg. Erythrovariae, sect. Variae) and its related sexual species in Japan.

Apogamous fern species are often difficult to distinguish from related species because of their continuous morphological variations. To clarify the genetic relationships among the members of the Dryopteris varia complex, we analyzed the nucleotide sequences of the plastid gene rbcL and the nuclear gene PgiC. We also analyzed the diploid sexual species D. caudipinna and D. chinensis, which have not been included in the complex, but were recently shown to be closely related to the complex in a molecular phylogenetic study. The PgiC sequences of the diploid sexual species, D. varia, D. saxifraga, D. sp. 'protobissetiana' (undescribed diploid sexual species), D. caudipinna, and D. chinensis, were well differentiated and hence designated A, B, C, D, and E, respectively. Thus, the PgiC constitution of apogamous species in the complex was as follows: D. bissetiana, B + C; D. kobayashii, B + C + E); D. pacifica, A + C, A + B + C, or A + C + D; D. sacrosancta, A + C + E; and D. saxifragivaria, B + C. These results suggest that these apogamous species are formed by hybridizations of species including not only the three diploid sexual species of the D. varia complex (A, B, and C) but also the two diploid sexual species D. caudipinna (D) and D. chinensis (E), which do not belong to the complex.

Personality Traits Associated with Treatment Choice with an Explicit Statistical Prediction After an Explanation in a Negative Context: A Study in Patients with Glaucoma.

Purpose: Over 50% of patients with early-stage glaucoma discontinue topical therapy within the first 6 months of treatment initiation. This risk of discontinuation could be reduced by how the ophthalmologist explains the treatment plan. Ophthalmologists can explain the treatment plan to patients in either positive or negative contexts. Although explanations in a negative context can be selected depending on the medical situation, identification of patients who will choose the treatment with explicit statistical prediction after an explanation in a negative context is important; personality traits are related to these emotional decisions. Therefore, in the present study, we examined the personality traits associated with choice of treatment with explicit statistical prediction after an explanation in a negative context. Patients and Methods: A total of 147 patients with glaucoma were recruited for this study. The questionnaire booklets used contained positively framed or negatively framed versions of an "Asian disease problem" to enable examination of the influence of the way in which a problem is framed (framing effect) on the participants' decision-making. The Japanese version of the Ten-Item Personality Inventory was used to estimate the personality traits of the participants. Results: Low conscientiousness was identified as the only variable that was strongly predictive of the choice of treatment with explicit statistical prediction (ß = -0.44, z = 2.19, p = 0.03). In addition, while the association was not statistically significant, low neuroticism was found to be weakly predictive of the choice of uncertain treatment (ß = -0.37, z = 1.73, p = 0.08). Conclusion: In conclusion, we showed that low levels of conscientiousness predict the choice of treatment with explicit statistical prediction (ie, topical treatment) for glaucoma after an explanation in a negative context.

Thylacopterisminuta (Polypodiaceae), a new fern species from Myanmar.

The genus Thylacopteris is a small, phylogenetically isolated genus belonging to the fern family Polypodiaceae. This study describes a new species, Thylacopterisminuta, based on collections obtained during field surveys of Shan State, Myanmar. This new species is distinct from other species of Thylacopteris in its small size and presence of sclerenchyma strands in the rhizome. This species is also distinct from the only other species of Thylacopteris with molecular data available, T.papillosa, in a plastid rbcL phylogeny of Polypodiaceae. This new discovery of Thylacopteris from Myanmar suggests that this genus is still overlooked in Southeast Asia.

Efficacy and Safety of Omidenepag Isopropyl 0.002% Ophthalmic Solution: A Retrospective Analysis of Real-World Data in Japan.

INTRODUCTION: This study aimed to clarify the efficacy and safety of omidenepag isopropyl (OMDI) in a retrospective, real-world, multicenter setting. METHODS: A retrospective medical chart review of patients with glaucoma and ocular hypertension receiving OMDI from November 2018 to November 2019 with at least 12 weeks of follow-up was conducted in 11 eye clinics in Japan. The participants were categorized into three therapy groups, designated the naïve monotherapy, switching monotherapy, and concomitant therapy groups. The main outcome measures were the change in intraocular pressure (IOP) at week 4 and week 12 after the initiation of OMDI treatment, and frequency of adverse drug reactions. RESULTS: Data were collected from 827 patients. The baseline IOP in the naïve group was 16.6 ± 4.2 mmHg. The mean IOP reduction at week 4 and week 12 was - 2.9 ± 3.2 mmHg (P < 0.0001) and - 2.5 ± 2.9 mmHg (P < 0.0001), respectively. Eyes with baseline IOP less than 16 mmHg also showed a significant reduction of IOP of - 1.4 ± 2.0 mmHg at week 12. OMDI significantly reduced IOP not only in eyes with primary open-angle glaucoma but also in eyes with primary angle-closure glaucoma and secondary glaucoma. In the switching monotherapy group, IOP did not change significantly after switching from most classes of medications to OMDI, but further IOP reduction was observed in the case of switching from beta-blockers to OMDI. The frequency of adverse drug reactions was 14.1% in all participants, and the most common adverse reaction was ocular hyperemia (7.6%). No serious and severe side effects were observed in this study. CONCLUSION: OMDI showed an IOP-lowering effect in eyes with various types of glaucoma and using various therapeutic regimens in real-world clinical practice. In addition, OMDI did not show any serious and severe side effects, suggesting the potential of OMDI as a first-line medicine for the treatment of glaucoma. TRIAL REGISTRATION: University Hospital Medical Information Network (UMIN): 000040040.

Lepisorusmedioximus (Polypodiales, Polypodiaceae), a new species from Shan State of Myanmar.

A new species of the species-rich fern genus Lepisorus (Polypodiales, Polypodiaceae) has been found to occur in Shan state, Myanmar. Lepisorusmedioximus is described based on morphological characters and phylogenetic evidence. Phylogenetic analyses showed that the specimens of L.medioximus formed a distinct clade nested in the Pseudovittaria clade. The morphological comparison demonstrated that the species is distinct from phylogenetically related species, namely L.elegans, L.contortus, and L.tosaensis, in the morphology of the rhizome scales, size, and shape of the lamina, position of sori, and paraphyses.

Association between personality traits and experience of adverse periocular reactions to topical prostaglandin analogues.

BACKGROUND: Aesthetically unappealing adverse periocular reactions to prostaglandin (PG) eye-drops are a major challenge in glaucoma treatment. This study analysed the personality traits of patients with glaucoma based on a five-factor model and examined the associations between these factors and adverse periocular reactions. METHODS: One hundred and forty-seven patients with glaucoma were surveyed anonymously regarding their personality traits and how often adverse periocular reactions were experienced. RESULTS: The analysis included 117 valid responses (71 men and 46 women, age: 61.9±11.5 years). Patients who experienced hypertrichosis of the eyelashes scored significantly higher on extraversion (p<0.05), with no significant differences in the other four personality traits. Patients who experienced eyelid hyperpigmentation and deepening of the upper eyelid sulcus showed no significant differences in any of the personality traits. Younger patients scored significantly higher on hypertrichosis (p<0.05). CONCLUSION: The experience of adverse reactions differed according to patient age and personality traits. Therefore, eye-drops should be chosen based on these factors. TRIAL REGISTRATION NUMBER: UMIN000035155.

Two new hybrids of the genus Diplazium (Athyriaceae) from Japan.

In this study, we describe the ferns Diplazium × kanayamaense hyb. nov. and D. × tsukushiense hyb. nov. and further compare them to parental species D. chinense, D. deciduum and D. fauriei in terms of morphological characteristics, plastids and nuclear DNA markers. These new hybrids have been determined to be endemic to western Japan. The International Union for Conservation of Nature and Natural Resources status was evaluated for D. × kanayamaense as endangered (EN) and D. × tsukushiense as critically endangered (CR).

Twenty-Four-Hour Intraocular Pressure Control with Omidenepag Isopropyl 0.002% in Patients with Glaucoma and Ocular Hypertension.

PURPOSE: To clarify the intraocular pressure (IOP)-lowering effect of a selective prostanoid EP2 receptor agonist, omidenepag isopropyl (OMDI) during a 24-hour period. PATIENTS AND METHODS: Subjects aged ≥20 years and with diagnosed, untreated primary open-angle glaucoma or ocular hypertension were enrolled. IOP measurements were performed every 4 hours over a 24-hour period using a Goldmann applanation tonometer (GAT) and Icare PRO tonometer (PRO). The baseline 24-hour IOP was measured in untreated subjects. After the baseline measurements, participants were given OMDI 1 drop once daily at night for 4 weeks. At week 4, the IOP measurement was repeated under the same conditions. Diurnal (9 am, 1 pm, 5 pm) and nocturnal (9 pm, 1 am, 5 am) IOP measurements were compared between baseline and treatment with OMDI. Safety measures included adverse events, slit-lamp biomicroscopy, visual acuity, heart rate and blood pressure. RESULTS: Of 27 participants enrolled, 25 patients (20 males and 5 females, average age 52.2 ± 8.5 years) completed the study. In the sitting position, the baseline diurnal and nocturnal mean IOPs (GAT) were 19.1 ± 2.1 mmHg and 18.2 ± 2.6 mmHg, respectively, the diurnal and nocturnal mean IOP reduction from baseline were -2.8 ± 2.6 mmHg (p < 0.0001) and -3.3 ± 2.9 mmHg (p < 0.0001), respectively, mean 24-hour IOP (GAT) was significantly lower with the OMDI treatment (-3.1 ± 2.5 mmHg, p < 0.0001). In the supine position, the baseline nocturnal mean IOP (PRO) was 17.99 ± 2.22 mmHg, and the nocturnal mean IOP reduction from baseline was -1.78 ± 2.37 mmHg (p = 0.0009) after 4 weeks of the treatment. Nine adverse events were observed in 8 patients including mild conjunctival hyperemia (n = 8) and mild iritis (n=1). There were no significant effects on systemic safety. CONCLUSION: Once daily OMDI treatment was able to produce stable 24-hour IOP reduction.

Deparia × nanakuraensis K.Hori (Athyriaceae), a new hybrid pteridophyte from Japan.

I describe Deparia × nanakuraensishyb. nov. and discuss differences in morphological characteristics between parental species D. pterorachis and D. viridifrons with chromosome counting, plastid, and nuclear DNA markers. The new hybrid is endemic to the eastern and northern parts of Japan. Based on the criteria of the International Union for Conservation of Nature and Natural Resources, this new species is here considered Data Deficient. The ploidy level is diploid sterile.

Athyrium bipinnatum K.Hori (Athyriaceae), a new cornopteroid fern from Japan.

I describe Athyrium bipinnatum sp. nov. and discuss morphological differences between closely related species. The new species is endemic to Japan, occurring on the islands of Honshu, Kyushu, and Shikoku. Based on the criteria of the International union for conservation of nature and natural resources, this new species is here considered endangered.

Origin of the Diplaziumhachijoense complex (Athyriaceae).

We analyzed the phylogeny of the Diplaziumhachijoense complex using plastid trnL-F and low-copy nuclear marker AK1 DNA sequences. Based on allele constitution, triploid apogamous species of the D.hachijoense complex appeared to have originated from the hybridization of triploid apogamous species and diploid sexual species by recurrent hybridization events. These results suggested that triploid apogamous ferns can achieve hybridization with diploid sexual species by producing diploid spores with irregular meiosis in sporogenesis. Furthermore, the present study predicted the involvement of several unknown species associated with hybridization. More sampling of Callipteris species from China and adjacent areas is required to determine the relationships among unknown species and the D.hachijoense complex.