Orally disintegrating olanzapine review: effectiveness, patient preference, adherence, and other properties.

Orally disintegrating olanzapine (ODO) is a rapid-dissolving formulation of olanzapine which disintegrates in saliva almost immediately, developed as a convenient and adherence-enhancing alternative to the standard olanzapine-coated tablet (SOT). Clinical studies, which form the basis of this review, have shown ODO and SOT to have similar efficacy and tolerability profiles. However, ODO appears to have a number of advantages over SOT in terms of adherence, patient preference, and reduction in nursing burden. Overall, the existing clinical data suggests that compared to SOT, ODO is not only well-suited for difficult-to-treat, agitated, and/or nonadherent patients but, due to its potential ability to improve adherence and greater patient preference, may also be an appropriate formulation for the majority of patients for which olanzapine is the antipsychotic of choice.

A 12-month prospective, observational study of treatment regimen and quality of life associated with ADHD in central and eastern europe and eastern Asia.

OBJECTIVES: This prospective, observational, non-randomized study aimed to describe the relationship between treatment regimen prescribed and the quality of life (QoL) of ADHD patients in countries of Central and Eastern Europe (CEE) and Eastern Asia over 12 months. METHODS: 977 Male and female patients aged 6-17 years seeking treatment for symptoms of ADHD were assessed using the Child and Adolescent Symptom Inventory-4 Parent Checklists, and the Clinical Global Impressions-ADHD-Severity scale. QoL was assessed using the Child Health and Illness Profile-Child Edition parent report form. Patients were grouped according to whether they were prescribed psycho- and/or pharmacotherapy (treatment) or not (no/'other' treatment). RESULTS: No statistically significant differences were observed between cohorts (treatment vs. no/'other' treatment) in terms of change in QoL, although there was improvement over 12 months, with a greater improvement experienced by patients in the treatment cohort in both study regions (CEE and Eastern Asia). Psychoeducation/counselling and methylphenidate were the predominant ADHD treatments prescribed. CONCLUSIONS: Although both treatment and no/'other' treatment cohorts showed improvements in mean QoL over 12 months, the difference was small and not statistically significant. A major limitation was the higher than anticipated number of patients switching treatments, predominantly from the no/'other' treatment cohort.

Academic outcomes in Asian children aged 8-11 years with attention-deficit/hyperactivity disorder treated with atomoxetine hydrochloride.

OBJECTIVE: To investigate the relationship between changes in attention-deficit/hyperactivity disorder (ADHD) core symptoms and changes in academic outcome of Asian children treated with atomoxetine. METHODS: This open-label study enrolled patients aged 8-11 years with DSM-IV-TR-defined ADHD, who were naïve to ADHD medications and met the symptomatic severity threshold of 1.5 standard deviations above the age and gender norm for the ADHDRS-IV-Parent:Inv (ADHDRS) total score. Data collection occurred for 24 weeks and included academic outcome, measured by the school grade average (SGA). RESULTS: Of 228 patients enrolled from China (n = 82), Taiwan (n = 76), and Korea (n = 70), 77.2% completed the study. Statistically significant (P < 0.001) baseline to last observation improvements in ADHDRS and SGA scores were observed. However, no linear correlation between change in ADHDRS total score and SGA (-0.083, P = 0.293) was observed. CONCLUSIONS: Despite significant independent improvements in core ADHD symptoms and academic grades over 24 weeks, the mean improvements observed in these measures did not appear to be correlated.

Molecular characterization of interleukin-1Beta in the tammar wallaby (Macropus eugenii).

Interleukin-1beta (IL-1ß) plays a significant role in the onset and pathogenesis of inflammation in mammalian hosts. Although well characterized in a range of vertebrate species, little is known about this important cytokine in marsupial mammals. We report here the molecular cloning and characterization of IL-1ß in the tammar wallaby (Macropus eugenii). M. eugenii IL-1ß has an open-reading frame of 813 nucleotides, coding for a putative protein of 270 amino acids to the termination codon. The IL-1 family motif and potential caspase cleavage site (necessary for production of the mature protein) is also present in the sequence. Molecular characterization of tammar wallaby IL-1ß provides fundamental information necessary to progress the study of functional immune responses in this unique group of mammals.

Twelve-month prospective, multinational, observational study of factors associated with recovery from mania in bipolar disorder in patients treated with atypical antipsychotics.

OBJECTIVES: Atypical antipsychotic agents constitute one therapeutic approach for bipolar disorder. Since disease course and outcome are variable, further studies are needed to complement limited data supportive of clinical decisions at treatment initiation. METHODS: This 12-month, prospective, observational study investigated factors associated with symptomatic remission (total YMRS score < or =12) and full clinical recovery (sustained reduction in CGI-BP-S overall score) in bipolar disorder during treatment with atypical antipsychotics (predominantly olanzapine, risperidone and quetiapine; alone or in combination with a psychotropic such as lithium or valproate) in actual clinical practice. RESULTS: Amongst 872 enrolled and eligible patients, rates of symptomatic remission and full clinical recovery at 12 months were 93.0 and 78.5%, respectively. Of the baseline factors significantly (P< or =0.05) associated with symptomatic remission, the following categories were positively associated with a higher chance of symptomatic remission: Caucasian ethnicity; higher CGI-BP-S scores; family-dependent living; a previous manic episode; 1, 2 or > or =5 social activities; no work impairment; and being neither satisfied nor dissatisfied with life. Outpatient treatment and historically longer periods of mania were significantly positively associated with full clinical recovery. CONCLUSIONS: While clinical status may also be associated with longer-term remission and recovery, factors relating to social functioning and quality of life are easily assessed and potentially modifiable. Such knowledge may aid physicians' clinical decisions regarding patients with bipolar mania treated with atypical antipsychotics.

A prospective observational study of attention-deficit/hyperactivity disorder in Central and Eastern Europe and Turkey: Symptom severity and treatment options in a paediatric population.

Abstract Objective. This study investigates the relationship between treatment regimen, symptom severity, comorbidities and health outcomes of paediatric patients with attention-deficit/hyperactivity disorder (ADHD) in Central and Eastern Europe (CEE). Methods. Males and females aged 6-17 years with ADHD symptoms participated in this 12-month, prospective, observational, non-randomised study. Symptoms and comorbidities were assessed using the Child and Adolescent Symptom Inventory-4 Parent Checklists (CSI-4; ASI-4, categories L/O), and the Clinical Global Impressions-ADHD-Severity scale (CGI-ADHD-S). Baseline data are presented. Results. The study included 566 patients from Czech Republic, Hungary, Romania, Slovakia and Turkey. Psychiatrists made all diagnoses using The American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV), World Health Organization International Statistical Classification of Diseases and Related Health Problems, 10th Revision (ICD-10), and "other" criteria (73, 27 and 0.4%, respectively). Patients were grouped into two cohorts based on whether they were prescribed psycho- and/or pharmacotherapy (n=443) or not (n=123). Patients receiving prescribed treatment were older and demonstrated higher symptom severity scores than those receiving no or "other" treatment. Most patients were prescribed conventional treatment for ADHD at baseline. Conclusions. Continued assessment of this population may aid the treatment and outcomes of ADHD in CEE.

Attention-deficit/hyperactivity disorder diagnosis, co-morbidities, treatment patterns, and quality of life in a pediatric population in central and eastern Europe and Asia.

Attention deficit/hyperactivity disorder (ADHD) is often poorly understood, and treatment practices are variable. This 12-month, prospective, observational study provides information about the diagnosis, co-morbidities, treatment patterns, and quality of life (QOL) of patients aged 6-17 years with ADHD symptoms from eastern Asia and central and eastern Europe. Here, we present baseline data for the 1068 enrolled and eligible patients in the study (median age 8 years, 82.2% male). Patients were grouped into two cohorts based on whether they were prescribed psycho- and/or pharmacotherapy (n = 794) or not (n = 274) at study entry. On average, patients receiving treatment were significantly older (9.1 vs. 8.4 years, p < 0.001), more severely ill (Clinical Global Impressions [CGI]-ADHD-S, 4.6 vs. 4.2, p < 0.001; Child Symptom Inventory-4 Parent Checklist (CSI-4) ADHD:C, 35.2 vs. 31.9, p < 0.001), and had significantly higher CSI-4 symptom severity scores relating to various co-morbidities than patients not receiving treatment. At study initiation, patient's health-related QOL was significantly impaired as measured on the Child Health and Illness Profile-Child Edition (CHIP-CE) rating scale, with significantly more impairment in the treated group of patients for the Comfort, Risks Avoidance, and Achievement domains. These results provide a description of ADHD and treatment practices in these regions and establish a baseline for gauging changes over time in the study sample.

Longer-term treatment of patients with bipolar disorder: a 9-month observational study in Central and Eastern Europe, the Middle East and Africa.

OBJECTIVE: To compare the longer-term outcomes of pharmacological treatment of patients with a diagnosis of bipolar affective disorder currently suffering a manic or hypomanic episode prescribed olanzapine or non-olanzapine medication in naturalistic, clinical practice settings in Bosnia-Herzegovina, Slovakia, Slovenia, Turkey, Saudi Arabia and Egypt. RESEARCH DESIGN AND METHODS: Prospective, observational, non-interventional study conducted over 9 months. Inpatients or outpatients who initiated or changed oral bipolar mania medication were grouped into (1) those prescribed olanzapine at baseline (n = 569) and (2) those not prescribed olanzapine (n = 325). MAIN OUTCOME MEASURE(S): The change from baseline in the Clinical Global Impression Severity scale for bipolar disorder (CGI-BP-S), the rates of symptomatic response and remission (based on CGI-BP-S) and the frequency and nature of treatment-emergent adverse events. Analyses included (1) linear or logistic regression, with adjustment for confounders, based on the last observation carried forward and (2) weighted repeated measures models that adjusted for treatment switching and patient drop-out. RESULTS: When results were adjusted for treatment switching and patient drop-out, patients prescribed olanzapine had significantly better CGI-BP-S scores (mean difference = -0.24; 95% confidence interval [CI] -0.33, -0.16; p < 0.001) and significantly greater odds of treatment response (odds ratio [OR] = 1.86; 95% CI 1.31, 2.65; p < 0.001) and symptom remission (OR = 1.65; 95% CI 1.18-2.32; p = 0.003) than those not prescribed olanzapine. The frequency of most adverse events decreased in both groups. Patients prescribed olanzapine had significantly greater weight gain from baseline (mean increase = 2.66 kg; 95% CI 2.35, 2.98) compared with those not prescribed olanzapine (mean increase = 1.85 kg; 95% CI 1.51, 2.19; p < 0.001). CONCLUSIONS: Inclusion of olanzapine is of benefit for pharmacological treatment of patients with bipolar disorder. However, the favourable outcomes observed cannot be directly attributed to olanzapine alone because of the high prevalence of polypharmacy in the patient population.

Acute phase results from STORM, a multicountry observational study of bipolar disorder treatment and outcomes.

OBJECTIVES: This prospective observational study examined the outcomes associated with the treatment of bipolar mania in clinical practice settings in a diverse range of countries: Bosnia, Slovenia, Slovakia, Egypt, Saudi Arabia and Turkey. Particular emphasis was placed on investigating outcomes associated with treatment regimens including and excluding the atypical antipsychotic olanzapine. SUBJECTS AND METHODS: In- and outpatients initiating or changing oral medication for the treatment of bipolar mania were grouped into two treatment cohorts: (1) olanzapine (N=569), and (2) non-olanzapine (N=325). Clinical outcome measures included change in Clinical Global Impressions-Bipolar Version Severity of Illness scale (CGI-BP), Young Mania Rating Scale (YMRS) and Hamilton Depression Rating scale- 5 item (HAMD-5) scores, and response and remission rates. Outcomes were analysed by conventional linear or logistic regression, adjusted for potential confounders, using last observation carried forward (LOCF) at endpoint, and a marginal structural model (MSM) approach to account for treatment switching. Results from the 12-week acute phase are presented. RESULTS: Clinical improvements were observed in both cohorts. While no marked differences were apparent between the groups in adjusted mean baseline to LOCF endpoint change, longitudinal analysis of these variables using MSM averaged over all visits indicated greater improvements in the olanzapine versus non-olanzapine cohort in CGI-BP Overall (-0.26, p<0.001), CGI-BP Mania (-0.19, p<0.001), CGI-BP Depression (-0.10, p=0.003), CGI Psychosis (-0.14, p=0.001), YMRS (-1.70, p<0.001), and HAMD-5 (-0.40, p<0.001) scores. CONCLUSIONS: Inclusion of olanzapine after initiating or switching treatment for bipolar mania appeared to be beneficial during treatment in terms of symptom improvement.

Once-daily duloxetine 60 mg in the treatment of major depressive disorder: multicenter, double-blind, randomized, paroxetine-controlled, non-inferiority trial in China, Korea, Taiwan and Brazil.

The aim of the present paper was to compare the efficacy and safety of duloxetine with paroxetine in the acute treatment of major depressive disorder (MDD). In a randomized, double-blind trial of 8 weeks active treatment, patients with non-psychotic MDD were randomized to duloxetine 60 mg (n = 238) or paroxetine 20 mg (n = 240) once daily. Efficacy was primarily measured on change in the 17-item Hamilton Rating Scale for Depression (HAMD(17)) using a non-inferiority test with a margin of 2.2. Secondary efficacy measures included the HAMD(17) subscales, Hamilton Rating Scale for Anxiety, Clinical Global Impressions-Severity, Patient Global Impressions-Improvement, Somatic Symptoms Inventory and Visual Analog Scales (VAS) for pain. Safety measures included treatment-emergent adverse events (TEAE), vital signs, weight, laboratory analyses and electrocardiograms. Non-inferiority of duloxetine to paroxetine was demonstrated because the upper bound of the confidence interval for mean difference in HAMD(17) change (0.71) was less than the non-inferiority margin. Secondary efficacy end-points did not differ significantly between treatments with the exception of VAS back pain, where the pooled mean was lower in the duloxetine group (17.1) compared with the paroxetine group (20.3, P = 0.048). No significant differences were observed in the number of early discontinuations and overall TEAE. However, significantly greater proportions of patients in the duloxetine group experienced nausea and palpitations. No clinically relevant changes in laboratory values, vital signs, weight or electrocardiograms were observed with either treatment. The present study verifies the utility of duloxetine as an efficacious and safe treatment for both emotional and physical symptoms of MDD in this predominantly Asian patient sample.

Effectiveness and safety of olanzapine in the treatment of schizophrenia among Asian patients switching from conventional antipsychotics.

OBJECTIVES: The objectives of this study were: (1) to investigate, in a clinical practice setting, the effectiveness of olanzapine in the treatment of schizophrenia among partially-responding, symptomatic Asian patients who switch from conventional antipsychotic treatment, (2) to assess the safety of olanzapine and (3) to assess the change in quality of life in Asian patients with schizophrenia who switch to olanzapine. METHODS: Effectiveness, safety and quality of life were assessed in outpatients with schizophrenia (n=1267) who lacked symptomatic control with conventional antipsychotics and were switched to olanzapine therapy. Data for this prospective, observational study were collected for 12 months from Asian patients in China, Hong Kong, the Philippines, South Korea and Taiwan. RESULTS: Significant clinical improvements (P<0.05) were observed following 12 months of olanzapine treatment and 87.3% of the subjects responded to treatment at endpoint (i.e. Brief Psychiatric Rating Scale Total score reduced by > or =30% relative to baseline; last observation carried forward). Abnormal involuntary movements (mean change in Abnormal Involuntary Movement Scale: -3.20, P<0.001) and quality of life were significantly improved in patients treated with olanzapine. However, some patients experienced significant weight gain (3.60+/-4.50 kg, P<0.001) with olanzapine treatment, relative to baseline. CONCLUSIONS: This study shows that switching to olanzapine may be effective in improving symptoms, may be well-tolerated and may improve the quality of life in Asian patients who are only partially responsive to treatment with conventional antipsychotics. The pragmatic design and naturalistic setting of this large study make the findings relevant for treating patients from some Asian countries in routine clinical practice.

Heterogeneity-based genome search meta-analysis for preeclampsia.

Preeclampsia is a pregnancy-related disorder that causes maternal and fetal morbidity and mortality. Its exact inheritance pattern is still unknown, and genome searches for identifying susceptibility loci for preeclampsia have thus far produced inconclusive or inconsistent results. We performed a heterogeneity-based genome search meta-analysis (HEGESMA) that synthesized the available genome scan data on preeclampsia. HEGESMA identifies genetic regions (bins) that rank highly on average in terms of linkage statistics across genome scans (searches). The significance of each bin's average rank and heterogeneity across scans was calculated using Monte Carlo tests. The meta-analysis involved four genome-scans on general preeclampsia and five scans on severe preeclampsia. In general preeclampsia, 13 bins had significantly high average rank (Prank< 0.05) by either unweighted or weighted analyses, while four of them (2p11.2-2q21.1, 9q21.32-9q31.2, 2p15-2p11.2, 2q32.1-2q35) were formally significant by both analyses. Heterogeneity of bin 2.8 (2q32.1-2q35) was significantly low in both unweighted and weighted analysis (PQ< 0.01). In severe preeclampsia, 10 bins had significantly high average rank by either unweighted or weighted analyses and five of them (3q11.1-3q21.2, 2q37.1-2q37.3, 18p11.32-18p11.22, 2p15-2p11.2, 7q34-7q36.3) were significant by both analyses. Bin 2q37.1-2q37.3 showed marginal low heterogeneity in unweighted and weighted analysis (PQ= 0.06). Results should be interpreted with caution as the p values were modest. Further investigation of these regions by genotyping with additional markers and families may help to direct the identification of candidate genes for preeclampsia.

Effectiveness and tolerability of schizophrenia treatment in Central and Eastern Europe: results after 1 year from a prospective, observational study (IC-SOHO).

Objective. The Intercontinental Schizophrenia Outpatient Health Outcomes (IC-SOHO) study is intended to complement smaller, shorter-term observational studies and randomised controlled clinical trials in providing information on the treatment of schizophrenia in various geographies that have not been well studied previously. Methods. Interim results after 12 months are presented for a subset of patients from eight Central and Eastern European (CEE) countries initiating or switching to olanzapine, risperidone, or typical antipsychotic monotherapy at Baseline (n=1387). Results. Patients initially prescribed olanzapine and risperidone experienced significantly greater improvements in a broad range of schizophrenia symptom domains compared with patients prescribed typicals. Furthermore, patients in the olanzapine group showed significantly greater improvements in overall and negative symptom domains compared with the risperidone group (all P≤0.05). While patients in the olanzapine group gained more weight than the other two groups, they had significantly lower odds of developing extrapyramidal symptoms, loss of libido, and sexual dysfunction. Patients initially prescribed olanzapine were also significantly less likely to have changed or added antipsychotics during 12 months of treatment compared with the risperidone and typicals groups. Conclusion. In this CEE sample, schizophrenia treatment outcomes after 12 months varied between patients initially prescribed different antipsychotics.

Interferon alpha/beta genes from a marsupial, Macropus eugenii.

This paper describes the cloning of full length marsupial type I interferon (IFN) genes and their flanking regions using a genome walking approach and PCR primers based on previously isolated partial DNA sequences. We confirm that the two major classes of Tammar Wallaby type I IFN genes are homologous with the eutherian IFN-alpha and IFN-beta gene families. The wallaby IFN genes share a number of conserved features with their eutherian counterparts, including codons for cysteines at equivalent positions, implying similar secondary structures for the encoded proteins, and promoter regions with conserved putative regulatory motifs. Moreover, the wallaby genes have AT-rich elements in their flanking sequence corresponding to the mRNA 3'-untranslated regions, also implying that, as in eutherian mammals, rapid mRNA degradation plays a role in regulating expression of these genes. The complex nature of the type I IFN gene families in viviparous mammals (eutherians and marsupials) may reflect their recruitment into nonimmunological processes and this concept is discussed.

Isolation of monotreme T-cell receptor alpha and beta chains.

Monotremes are an ancient mammalian lineage that last shared a common ancestor with the marsupial and eutherian (placental) mammals about 170 million years ago. Characterization of their immune genes is allowing us to gain insights into the evolutionary processes that lead to the 'mammalian' immune response. Here we describe the characterization of the first cDNA clones encoding T-cell receptors from a monotreme. Two TCR alpha-chain cDNAs ( TCRA) from the short-beaked echidna, Tachyglossus aculeatus, containing complete variable, joining and constant regions were isolated. The echidna TCRA constant region shares approximately 37% amino acid identity with other mammalian TCRA constant region sequences. The two variable regions belong to the TCRAV group C, which also contains V genes from humans, mice, cattle and chickens. One echidna TCR beta-chain cDNA ( TCRB) containing the entire constant region was isolated and sequenced. It shares about 63% identity with other mammalian TCRB constant region sequences. The echidna TCRBV belongs to TCRBV group A, which also contains V genes from various eutherian species. Southern blot analysis indicates that, like in other mammalian species, there is only one TCRA constant region copy in the echidna genome, but at least two TCRB constant regions.

Type I interferon genes from the egg-laying mammal, Tachyglossus aculeatus (short-beaked echidna).

The type I IFN are an important group of multifunctional cytokines that have, for whatever reason, evolved to a high level of complexity in eutherian mammals such as humans and mice. However, until recently, little was known about the type I IFN systems of the other two groups of extant mammals, the marsupials and the egg-laying monotremes. Preliminary partial type I IFN sequences from the short-beaked echidna were previously found to cluster only with the IFN-beta subtype in phylogenetic analyses, but a lack of sequence information made interpretation of these results tenuous. Here, we report cloning of the full-length genes of representatives from the two previously defined groups of echidna type I IFN by genomic walking PCR. Along with analysis of conserved cysteine placement and promoter elements, phylogenetic analysis incorporating these sequences strongly suggest that the two groups of echidna type I IFN genes are in fact homologous to IFN-alpha and IFN-beta, confirming that the duplication leading to these two major classes of type I IFN occurred prior to the divergence of eutherians and monotremes some 180 million years ago. Thus, even though there are major differences in gene copy number and heterogeneity, separate IFN-alpha and IFN-beta gene families are a feature of the cytokine networks of all three groups of living mammals.

Primary structure and variation of the T-cell receptor delta-chain from a marsupial, Macropus eugenii.

Although gammadelta T-cells form only a small portion of circulating T-cells in mice and humans, they are more frequent in many other types of mammals and this has lead to speculation regarding their roles and the evolutionary significance of their relative abundance. Moreover, whilst clear homologues of four types of T-cell receptor (TCR) chains (alpha, beta, delta and gamma) have been identified in vertebrates as distantly related as eutherian mammals and cartilaginous fish, there are still many gaps in our knowledge of these TCR components from various taxa. Such knowledge would further illuminate the evolution and function of these receptors and of gammadelta T-cells. Here, we report the molecular cloning of a TCR-delta chain cDNA from the tammar wallaby (Macropus eugenii) which represents the first component of the gammadelta TCR to be characterised from a marsupial. A PCR-based survey of variable (V) segment usage in tammar wallaby mammary-associated lymph node indicated that, although gammadelta T-cells may be sparse in this type of tissue, this species has at least three subfamilies of V genes that have been broadly conserved across vertebrate evolution. Two V subfamilies found in the tammar wallaby were relatively similar and may have diverged more recently, an event that probably occurred at some point in the marsupial lineage.

A survey of type I interferons from a marsupial and monotreme: implications for the evolution of the type I interferon gene family in mammals.

Sequence data for type I interferons (IFNs) have previously only been available for birds and eutherian ('placental') mammals, but not for the other two groups of extant mammals, the marsupials and monotremes. This has left a large gap in our knowledge of the evolutionary and functional relationships of what is a complex gene family in eutherians. In this study, a PCR-based survey of type I IFN genes from a marsupial, the tammar wallaby (Macropus eugenii), and a monotreme, the short-beaked echidna (Tachyglossus aculeatus), was conducted. Along with Southern blot and phylogenetic analysis, this revealed a large number of type I IFN genes for the wallaby, rivalling that of eutherians, but relatively few type I IFN genes in the echidna. The wallaby genes include both IFNA and IFNB orthologues, indicating that the gene duplication leading to these subtypes occurred prior to the divergence of marsupials and eutherians some 130 million years ago. Results from this study support the idea that the expansion of type I IFN gene complexity in mammals coincides with a concomitant expansion in the functionality of these molecules. For example, this expansion in complexity may have, at least partially, facilitated the evolution of viviparity in marsupials and eutherians. Other evolutionary aspects of these sequences are also discussed.

The mammalian Crx genes are highly divergent representatives of the Otx5 gene family, a gnathostome orthology class of orthodenticle-related homeogenes involved in the differentiation of retinal photoreceptors and circadian entrainment.

The mammalian Crx genes are highly divergent orthodenticle (otd)-related homeogenes that play important roles in the differentiation of retinal photoreceptors and the circadian entrainment. However, their evolutionary origin and orthological relationships with other otd-related genes remain unclear. An orthology relationship of these genes with the highly conserved Otx5 genes identified in fish and amphibians, and also expressed in the eye and epiphysis, has been proposed previously but remains controversial. To test this hypothesis, we have identified Crx genes in a wide range of mammals, including three marsupials, and Otx5-related genes in a lizard, a turtle, and two archosaurs (crocodile and chick), as well as in the pufferfish. Phylogenetic analyses of the coding sequences show that the mammalian Crx genes are orthologous to the Otx5-related genes isolated in other gnathostomes. They also indicate that a duplication event has taken place in actinopterygians, after the splitting of the Cladistia, and that a relaxation of the structural constraints acting on the gene coding region has occurred early in the mammalian lineage. This process may be linked not only to the loss of ancestral Otx5/Crx functions during gastrulation or in the retinal pigmented epithelium, but also to the evolution of photic entrainment mechanisms in mammals.

The major histocompatibility complex in monotremes: an analysis of the evolution of Mhc class I genes across all three mammalian subclasses.

We report the isolation and characterization of cDNA clones of expressed, functional major histocompatibility complex class-I ( Mhc-I) genes from two species of monotremes: the duck-billed platypus and the short-beaked echidna. The cDNA clones were isolated from libraries constructed from spleen RNA, clearly establishing their expression in at least this one peripheral lymphoid organ. From the presence of conserved amino acid residues, it appears the expressed sequences encode molecules that likely function as classical Mhc-I. These clones were isolated using monotreme Mhc-I processed pseudogenes as probes. These processed pseudogenes were isolated from genomic DNA and, based on their structure, are likely independently derived in the platypus and echidna. When all the monotreme sequences were included in phylogenetic analyses, we found no apparent orthologous relationships between the platypus and echidna Mhc-I. Analyses that included a large number of Mhc-I sequences from other taxa support a separate monotreme Mhc-I clade, basal to a therian Mhc-I clade that is comprised of sequences from marsupial and placental mammals. The phylogenies also support the hypothesis that Mhc-I genes of placental mammals, marsupials, and monotremes are derived from three separate lineages of Mhc-I genes, best explained by two rounds of duplications and deletions. The first round would have occurred prior to the divergence of monotremes and therians, and the second prior to the divergence of marsupials and placental mammals. The sequences described here represent the first reported functional monotreme Mhc-I, as well as the first processed pseudogenes of any type from monotremes.